1 SUSTAINABLE DECOMMISSIONING: WIND TURBINE BLADE

REPORT FROM PHASE 1 OF THE ENERGY TRANSITION ALLIANCE BLADE RECYCLING PROJECT

With contributions from: 3

CONTENTS SUMMARY

Acknowledgements 2 Thirty years ago, it would have been hard to imagine that Summary 3 offshore wind could power every home in the UK. Today,

Report Scope 6 that target is one of the key pillars of the UK Government’s

Anatomy of a Wind Turbine Blade 8 climate change policy. This vision has been driven by the passion of wind industry pioneers to forge this new sector Defining ‘Circular’ and ‘Recycling’ 10 and make renewable energy a commercial reality. Governance Landscape 12

Future Market Opportunity 16

Current Methods of Blade Disposal 24

Composites Sector by Sector 28 With this has come an unrelenting drive to develop systems on oil and gas rigs. Both now face the challenge high-performance, next-generation wind turbines that of finding good solutions for decommissioning these Review of Composite Recycling Methods 36 will achieve the necessary energy capture and cost materials in the coming decades. Mechanical 39 efficiency. For the blades, composite layers of stiff For the wind sector, that is an urgent challenge here and carbon or glass fibres in a resin matrix were found to be now as the first generation of wind farms are starting to Thermal 40 the optimal material, delivering exceptional strength, reach the end of their service life. Longer term, by 2050, stiffness-to-density and flexibility in processing. Chemical 42 the global offshore wind industry will decommission As the wind industry has grown, it has become a major up to 85GW of capacity (cumulatively, and assuming Reprocessing 44 user of these materials, which have long been a solution a 25-year lifecycle). Onshore wind will decommission to design challenges in the oil and gas, aerospace, another 1,200GW. The oil and gas sector will likely begin Environmental Impact 50 automotive, defence and leisure industries. They are to decommission today’s composite pipelines around found in the pipe systems at oil and gas rigs, in car the same time. Academic Research 54 seats and interiors, aeroplane wings, bicycles, skis and The wind industry is already a major collaborator in many surfboards, to name but a few applications. Industry Innovation Programmes 60 new innovation programmes in the composites arena – Composite blades are now the final hurdle towards Carbo4Power, SusWIND and the Circular Economy for Recommendations and Next Steps 72 fully recyclable wind turbines (85-90% of a turbine is the Wind Sector Joint Industry Project (CEWS). Under References 74 technically recyclable already1). At the end of their lives, the latter project, ORE Catapult has set the target for an they have proven difficult and costly to reclaim and at-scale demonstration of wind turbine blade recycling in reprocess. To fully satisfy the sector’s future growth the UK within five years. plans and sustainability goals, finding the right solution The report sets out the huge opportunity for the for recycling them is becoming imperative, especially as UK supply chain in designing solutions to tackle the the first generation of wind farms are starting to reach recycling challenge and capturing a global market that the end of their 25-year lifecycles. encompasses 2.5 million tonnes of composites already ACKNOWLEDGEMENTS In the year of COP26, this is the moment for the wind in use in the wind energy sector. Many of the recycling and other industries to pause and take stock. Pooling technologies discussed in the report require further our collective experience and resources, we can achieve study but show promise in terms of the quality of This report was written by Lorna Bennet, Project the feats of engineering that will make the energy recovered materials. Engineer at the Offshore Renewable Energy transition and pan-sector circular economy a reality. (ORE) Catapult. ORE Catapult would like to thank Recycling is just the start. Moving turbines towards zero the following partners for their help and expertise This report is the result of one such cross-sector will be the next opportunity for the UK supply in compiling the report: collaboration between OGTC, Offshore Renewable chain through remanufacturing, , repowering and Energy (ORE) Catapult, University of Leeds and National upgrading of components too. If realised, a spin-off • Dr Anne Velenturf, Research Impact Fellow Composites Centre (NCC). It is the first phase in our circular economy from offshore wind could extend the at the University of Leeds work to identify, study and then demonstrate scalable, current projection of 60,000 jobs in the sector by an • Annabel Fitzgerald, James Lightfoot cost-effective, and sustainable composite recycling additional 20,000 jobs. and Jonathan Fuller of the National technologies that will be applicable to the wind industry. As you will find in these pages, there are many reasons Composites Centre (NCC) When it comes to blade recycling, collaboration for optimism in the many techniques and technologies • Jeff Hailey and Pamela Lomoro of OGTC between the wind and oil and gas sectors will be that are already being trialled in this area. We are excited crucial to accelerating recycling technologies for plastic at the prospect of taking these forward together with composites. Both sectors are users of glass and carbon our industry partners and showing how the wind turbine, fibre reinforced plastics, which have proven to be the workhorse of the clean energy revolution, will take its optimal materials for both wind turbine blades and pipe next steps towards circularity. 4 5

Table 1. Results of the GF = glass fibre Technology CF = carbon fibre GFRP = glass fibre reinforced plastic Review, ETA CFRP = carbon fibre reinforced plastic Blade Recycling % figures refer to material properties retained Project Phase 1 post recycling compared to virgin fibres

PROCESS TRL TRL COST SCALE END PRODUCT/ INNOVATION GFRP CFRP USES CHALLENGES IF REALISED, A SPIN-OFF Mechanical Grinding 9 6 Low Large GFRP powder for filler Microplastics and dust or reprocessing

Cement kiln 9 N/A Low Large Energy recovery and Potential pollutants CIRCULAR ECONOMY co-processing cement clinker and particulate matter

Thermal Pyrolysis 5 9 High Small Low quality GF High Energy Intensive quality CF (90%) Oils FROM OFFSHORE WIND from resins

Fluidised bed 4 5 High Small Good quality, clean CF Energy Intensive pyrolysis (70-80%) COULD EXTEND THE Microwave N/A 4 High Very Good quality CF (75%) Less energy intense assisted pyrolysis Small

Steam pyrolysis N/A 4 High Very High quality CF (>90%) Energy Intensive Small CURRENT PROJECTION

Chemical Solvolysis 5 6 High Small Good quality GF (70%) Additional cleaning High quality CF (90%) process required Matrix material Energy Intensive OF 60,000 JOBS IN

High temperature 4 4 High Very Good quality, High energy intensive and pressure Small clean CF Corrosive, high solvolysis pressure THE SECTOR BY AN Low temperature 4 4 High Very Good quality, clean CF Less energy intensive and pressure Small Epoxy monomers Acids required that are solvolysis difficult to dispose of ADDITIONAL 20,000 Electrochemical 4 4 Very Very Reasonable GF High energy intensive High Small Inefficient

Reprocessing Milled fibre 9 6 Low Large Powder additive/filler Microplastics and dust (post grinding) for tailored electrical & JOBS BY 2030. thermal conductivity

Chopped fibre 9 6 Low Medium Thermoplastic Handling of dry fibres (post pyrolysis/ compounding/SMC/ solvolysis) BMC, cement reinforcing, prepreg tape

Pellets 6 9 Low Medium Injection moulding Microplastics and dust (thermoplastic)

Non-woven 9 9 Low Medium Press moulding, resin Handling of dry fibres mat infusion, wet pressing, prepregs, semi-pregs and SMCs

Component 8 N/A Medium Very Structural components: Low impact as no need reuse Small bridge support, bike for energy intensive shelter, roofing, etc methods to reclaim and process materials 6 7

REPORT A KEY CONCLUSION OF THE REPORT IS THAT IF THE SCOPE WIND INDUSTRY IS TO HAVE SECURITY OF SUPPLY IN THE COMING YEARS,

This report is the conclusion of the first phase of the Energy ESTABLISHING RELIABLE Transition Alliance’s Blade Recycling Project. In Phase 2, the project partners ORE Catapult and OGTC will select the most promising AND EFFICIENT RECYCLING solutions from this study for further exploration and demonstration under the third and final phase of the project. PROCESSES IS A NECESSITY.

Here, the current methods of blade disposal are While the wind industry continues its work to recycling processes is a necessity. With that CRITERIA FOR ASSESSING reviewed, the future scale of composite blade develop more sustainable solutions2,3, recycling comes a positive financial case, as it is estimated decommissioning is projected, and the influence is one of the best solutions achievable for these that the resultant onward sale of materials could RECYCLING TECHNOLOGIES of a changing regulatory framework is evaluated. first-generation blades. And it is a solution that recoup up to 20% of decommissioning costs for will be needed imminently in order to meet the an offshore wind farm5. The next step is an outline and assessment of Each of the technologies and processes investigated minimum resource security that will sustain all the scenarios for recycling of glass and fibre As yet, there remains a technology gap for in this report are reviewed against core criteria for offshore wind’s ambitious growth pathway. Wind reinforced plastics that are under development recycling blades. While various technologies meeting the wind industry’s needs: turbines are increasing rapidly in number and size and trial or are establishing themselves across exist to recycle their composite materials, and (turbine capacity has increased from 1.5MW in ENVIRONMENTAL IMPACTS various sectors. The emphasis throughout is an increasing number of companies are offering 2005 to 12MW in 2021). on the feasibility of these technologies and composite recycling services, these solutions are COST IMPLICATIONS FOR TURBINE approaches for use at the scale and cost that A study completed by Topham et al4 concluded not yet widely available nor cost competitive. END-OF-LIFE MANAGEMENT will be required by a sector that is expected that the material demands to manufacture a That is why this report’s additional exploration of to decommission 40,000 to 60,000 tonnes of single large turbine are higher than the resources technologies at the research and development COMPLIANCE WITH A DYNAMIC REGULATORY composite materials in the next two years alone1. required to build two smaller turbines for the stage is so important. LANDSCAPE (INCLUDING HEALTH AND same power capacity. In addition, the quantity SAFETY, USE OF CHEMICALS AND It is worth highlighting at this point that the of carbon fibre utilised also increases as blades PROCESS EMISSION REGULATIONS) assumption that lies behind this project is that become longer in order to achieve the necessary blade recycling will be a stepping-stone towards stiffness without significantly increasing weight. STAGE OF TECHNOLOGY DEVELOPMENT even more sustainable solutions in the future, and for this reason, some early examples of blade Landfill, which has been the most common USEFULNESS AND VALUE OF reuse in civil engineering and construction are solution for blade disposal to date, is out of the THE END PRODUCTS touched upon too. question as a future destination of these blades; primarily, as it does not match the industry’s own This is in tune with the philosophy of a circular ambitions for circularity and sustainability. The Three main forms of material reclamation were economy: designing out all waste at the start is report concludes that this momentum from the identified: mechanical, thermal and chemical. Once the ultimate end point of this journey, but one wind industry itself is proving to be the crucial fibres and other materials have been recovered, further that will not be achieved imminently. The next driver towards recycling. steps are required to reprocess them into usable best solutions are lifetime extension of turbines materials which can be recycled in the manufacture and components, repowering of whole wind A key conclusion of the report is that if the wind of new products and components across a wide farms and a whole host of refurbishing, reuse, industry is to have security of supply in the range of industries. and remanufacturing approaches too. coming years, establishing reliable and efficient 8 9 ANATOMY OF A WIND

Blades are typically constructed of a polymer resin matrix that is reinforced with glass fibres and carbon fibres. A hybrid of glass and carbon fibres is also increasingly coming into use in the industry. A laminate TURBINE BLADE core material, often made from high density foam or balsa wood, provides additional strength. The exterior of the blade is coated for weather protection Figure 1. Generic Composition of a Wind Turbine Blade6 and improved aerodynamic performance. There are also some metal components associated with the lightning protection Sandwich-Foam PVC Glass TX Adhesive Gel-coat system which prevents damage to the blade in the event of a lightning strike.

Adhesive Structural Carbon UD Laminate Sandwich-Foam PMI Glass Bx Adhesive 10 11 DEFINING ‘CIRCULAR’ AND ‘RECYCLING’ DEFINING ‘CIRCULAR ECONOMY’ DEFINING ‘RECYCLING’

A Circular Economy is seen as an alternative to a There is some ambiguity around what constitutes true linear economy, or the ‘take-make-dispose’ model. recycling. The UK’s Chartered Institution of ‘Recycling’ and ‘Circular Economy’ are terms in common parlance, Its aim is to keep resources in circulation, which Management defines it as: “Any operation the principal but they are too often confused or wrongly applied. Recycling is just means serving a useful purpose and for as long as result of which is waste serving a useful purpose by possible. This approach requires us to extract the replacing other materials which would otherwise have one of the solutions that can form part of a circular economy, but a maximum value from components while they are been used to fulfil a particular function, or waste being circular economy is much more than just one component or even one in use, then recover and regenerate products and prepared to fulfil that function, in the plant or in the materials at the end of each service life8. wider economy9”. While the Department for Environment, industry. It is an entire economic system aimed at eliminating waste Food and Rural Affairs (DEFRA) have described it The objectives of a Circular Economy are to: more succinctly as “turning waste into a new substance and ensuring continual use of resources. 10 • Reduce waste or product ”.

Figure 2. © 2020 by University of Leeds • Reduce the environmental impacts of The question is whether this is simply the collection and Circular Economy Strategies7 production and consumption preparation (or ‘harvesting’ and ‘reclamation’) of wastes Attribution-NonCommercial-ShareAlike into their core materials, or whether that operation must 4.0 International (CC BY-NC-SA 4.o) • Drive greater resource productivity and efficiency be followed by reprocessing into new products to qualify them as ‘recycled’. The latter is implied by den Hollander • Address emerging concerns with regard et al: “The recycling process involves the dismantling to resource security and scarcity Dematerialisation and disintegration of a product and its constituent When this report refers to ‘Circular Economy’ in the components and the subsequent reprocessing of the wind sector, it is referencing strategies that form a product’s materials” 11. coherent design for circularity across all stages of For the purposes of this project, the focus is towards the a wind farm’s life. reclamation and reprocessing of composites into materials that are in good enough condition for a future reuse. Reduce waste These strategies can be grouped into four main areas:

Narrowing resource flows, which means using less Related definitions resources to begin with, and thus limiting waste. Repair, There are a number of other definitions that will be used maintenance Slowing resource flows through repair, reuse and in this report that should not be confused with ‘recycling’: Lifetime remanufacturing strategies as well as lifetime Disassembly Repair: preventative, planned or ad hoc inspection/ extension extension and repowering of wind farm sites. servicing tasks, which may involve repairs to restore Recycling Reuse, refurbish, Closing resource flows hrough recycling of a component to a good working condition. upgrade components, decommissioning and re-mining. Repowering Remanufacturing: components are sorted, selected, Integrating resource flows by entrusting disassembled, cleaned, inspected and repaired/replaced Energy recovery Remanufacture materials to natural biogeochemical processes before being reassembled and tested to function as good during site restoration and landfill. as new or better.

Component reuse and : components are used again for the same (reuse) or different Landfill Decommissioning (repurpose) function.

Harvesting: the act of collecting and sorting fibre reinforced plastic waste.

Reclamation: the process of separating the fibres and resin. Re-mine Site restoration Reprocessing: where the reclaimed fibre is used to produce a useful material form, such as a discontinuous fibre mat. Materials Products and components Infrastructure 12 13 GOVERNANCE ENERGY, INFRASTRUCTURE AND CIRCULAR ECONOMY LANDSCAPE GENERALLY PERSIST IN POLICY SILOES BUT MOVES ARE UNDERWAY TO ALIGN THESE AREAS OF GOVERNANCE In the UK, the decommissioning of offshore wind farms is regulated by the Energy Act 200412 and the provision of a decommissioning MORE CLOSELY. programme is part of the consent process prior to development. While decommissioning programmes are primarily concerned with financial assurances to cover the costs of offshore wind decommissioning, recent research found that currently the regulation fails to do so2. Moreover, proposed decommissioning operations were found to be neither attuned environment or human health, and the polluter-pays more demands on the wind industry and require principle22; which for the offshore wind sector, means that companies invest now in the processes that to minimal resources and standards nor sensitive to that the responsibility of waste management and will deliver them. its costs falls on original equipment manufacturers resource security concerns about meeting the material demands that will Resources and waste regulation are highly dynamic, (OEMs) and operators, and to a lesser extent on 2 but the continued direction of travel is towards the sustain the sector’s ambitious growth pathway . operations and maintenance (O&M) providers. diversion of waste materials (that can be reused or Following Brexit, the European Commission’s Circular recycled) from going to incineration or landfill facilities. Overall, the general direction of travel in the UK is for On the other hand, the Maximising Economic Recovery Economy Package was transposed into UK law. This could limit the potential for turbine blades, which clean growth and a circular economy, as set out in the (MER) policy, implemented by the Oil & Gas Authority21 A brief overview of the strategy for the UK and predominantly consist of glass fibre reinforced plastics, Industrial Strategy13. Within the governance system, goes against the Clean Growth Strategy. This affects devolved nations backs up these ambitions. The to enter processes aimed primarily at energy recovery. however, energy, infrastructure and circular economy decommissioning, as the MER obliges operators Resources and Waste Strategy (RWS) for England Despite provisions to limit incineration of technically generally persist in policy siloes14: Energy is handled to continue extraction. It also affects the offshore aims to double resource productivity and eliminate recyclable materials, a part of the waste sector is by the Department for Business, Energy and Industrial wind sector by presenting a continued push to lower all avoidable waste by 2050. The Strategy forms part campaigning for large-scale investment into more Strategy (BEIS); infrastructure is part of the Treasury’s short-term levelised cost of energy (LCOE). of the Government’s commitment under the 25 Year Energy from Waste (EfW) capacity in the UK25. Already, activities; while resources and circular economy sit with Environment Plan to leave the environment in a better more than 80% of investment into waste management Circular economy (Department for Environment, Food and Rural Affairs state than we inherited it, including eliminating all infrastructure is directed towards energy-from-waste avoidable plastic waste. facilities or facilities to prepare refuse derived fuel26. (DEFRA). However, there have been recent moves to Circular Economy primarily concerns itself with the align these areas of governance more closely. The risk is that waste incineration becomes locked in stocks and flows of materials and products within the The Welsh Government’s strategy, Beyond Recycling, and UK plc loses valuable business opportunities, as economy. As such, the circular economy primarily sets out its aim of making a circular, low carbon Energy and climate observed already in Scandinavian countries27. pertains to policy and regulation on resources and economy in Wales a reality with a set of key actions Growth of wind power started relatively slowly, but the waste, which are largely driven by the EU Circular to deliver the objective of by 2050. The Stern Review (2006)15 and Climate Change Act 200816 Economy Package – a major pillar of the European Scottish Government’s circular economy strategy, raised ambitions for faster deployment17 by introducing Green Deal – and the Waste Framework Directive22,23. Making Things Last, published in 2016, sets out a clear legally binding greenhouse gas reduction targets for Major aspects of the EU Circular Economy Action Plan vision and priorities for action to move towards a the UK. In 2019, the UK Government set a net-zero are the reduction of average per capita consumption more circular economy; and Scotland has set a series THE RISK IS THAT WASTE target for carbon emissions by 2050 and reforming and the doubling of the use of recovered materials of ambitious targets to drive circularity. In Northern INCINERATION BECOMES the energy system is a major pillar of the low-carbon by 2030. Some materials and components that Ireland, the Department of Agriculture, Environment transition. Arguably the Clean Growth Strategy will are commonly used in offshore wind are already & Rural Affairs (DAERA) is currently developing the LOCKED IN AND UK PLC be followed by a new Integrated National Energy prioritised (such as electronics and electrical items, Environment Strategy for Northern Ireland, which will LOSES VALUABLE BUSINESS and Climate Plan, but so far only a draft version from steel and cement). consider the main long-term environmental priorities 18 2019 could be located online . Low-carbon energy for Northern Ireland.”24 OPPORTUNITIES, AS The Waste Framework Directive sets out the legislative has seen a strong growth19, but further reforms of the framework for waste handling and establishes key OBSERVED ALREADY IN energy system are necessary, and a more integrated At the UK level, the forthcoming Environment principles such as the , managing governance structure should be brought into place to Bill is expected to enshrine more ambitious targets SCANDINAVIAN COUNTRIES. wastes in a manner that does not harm the allow for flexible adaptive governance20. into law. The anticipated higher ambitions will place 14 15

Decommissioning will enable a feedback loop to the design of wind farms, to adapt the design with a view to optimise Offshore wind decommissioning is primarily THE RECOMMENDED APPROACH performance from environmental, social and governed by provisions made in the Energy Act economic perspectives at each stage of the lifecycle. 2004 implemented with guidance prepared by BEIS IS TO PROACTIVELY WORK which states that: “The Government’s approach is to While industry is in the first instance responsible for seek decommissioning solutions which are consistent the preparation of a decommissioning programme with relevant international obligations as well as UK of sufficient quality, Government can step in and WITH THE REGULATOR AND TO legislation, and which have a proper regard for safety, prepare the programme on their behalf if necessary the environment, other legitimate uses of the sea and (under Section 107 of the Energy Act 2004). economic considerations including protection of the The Energy Act also applies to repowering, but more taxpayer from liabilities relating to decommissioning. PREVENT A MATERIAL FROM clarity is required to understand the extent to which The Government will act in line with the principles of decommissioning programmes must be amended sustainable development.”34 in the case of repowering and whether this also BECOMING CLASSED AS A There is a general lack of detail in offshore wind applies to cases of lifetime extension. As previously decommissioning programmes regarding the waste mentioned, decommissioning became a devolved WASTE IN THE FIRST PLACE. management operations and a high likelihood that matter in 2017, with decommissioning responsibilities costs have been significantly underestimated. This and powers being transferred to the Scottish suggests that the first two obligations regarding the Government35. Marine Scotland has expressed the contents of decommissioning programmes have not inclination to stay close to legislation laid out for yet been met: England and Wales36.

• Programmes must set out measures to be taken for decommissioning the relevant object; Incineration of turbine blades is regulated under Companies can make their own assessment: however, • Plans must contain an estimate of the the Industrial Emissions Directive (IED)28, which this is risky as the regulator can sue companies as expenditure likely to be incurred in carrying out works in accordance with Best Available Techniques evidenced by the fact that End-of-Waste is riddled those measures. (BAT). The combustion of wind turbine blades does with case law. The recommended approach is to not appear to be specifically mentioned in existing proactively work with the regulator and to prevent Should best environmental solutions not be available BATs or BAT Reference Documents (BREFs)29 but a material from becoming classed as a waste in the in line with circular economy and sustainable the BREF on cement does mention glass fibre30. first place. If a recyclate remains classed as a waste development policies, i.e. to deliver absolute IED permits are subject to continuous improvement after recovery processing, then the commercial environmental improvements, then it can be argued THERE IS A giving consideration to evidence that the proposed value of the material may be significantly less, that the precautionary principle applies. In those technology is low waste and contributes to further possibly rendering investment in associated cases, the offshore wind sector can specify the GENERAL LACK recovery of materials, advances in the (academic) recycling processes uneconomical. knowledge gap and co-produce plans as part knowledge base, and minimising environmental of the decommissioning programme to increase OF DETAIL IN While landfilling wind turbine blades is not prohibited risks and impacts. chances that solutions will be available in support of anywhere in the UK (as in some European countries), environmental sustainability at every lifecycle stage, OFFSHORE WIND The end-of-waste regulations and the procedures available landfill space is rapidly diminishing. The including waste management. This will have the through which end-of-waste solutions are assessed landfill tax makes it economically unattractive. Scotland added benefit of reducing decommissioning costs DECOMMISSIONING by the regulator involve four tests, each of which and Wales, along with several EU countries, have or even opening new income streams for the sector. must be met: already begun severely limiting landfill. When it comes PROGRAMMES to export of wastes, the relevant legislation is the BEIS (2019) states that: “Waste from 1. Evidence that the recycled product is different Transfrontier Shipment of Waste Regulations 200731. decommissioning should be reused, recycled or from the original waste, and for meeting this Shipment to or from the UK is subject to a permit, incinerated with energy recovery in line with the REGARDING test a mechanical recycling route is normally regulatory fees for every shipment and very strict rules. waste hierarchy, with disposal on land as the last not sufficient; option”. This does not integrate recent updates THE WASTE The current general interpretation of the regulation 2. Presence of a clear and demonstrable market, to resources and waste policies, however, and the is that the export of wastes for which a solution can which may need to be developed as part of implications for waste management in offshore MANAGEMENT be reasonably found or brought into place inside the achieving end-of-waste; wind decommissioning will be greater proactivity UK is in principle not allowed. Moreover, in recent on decommissioning and waste management in OPERATIONS times the major destinations for waste from the UK, 3. The product can be used in the same way as a non- the design of wind farms and the manufacturing primarily in Asia, are tightening their rules and have waste alternative; usually this is assessed through of components. AND A HIGH a comparison with an appropriate virgin material; stopped accepting numerous low-value materials. When exporting to countries with more lenient waste A more proactive approach would include LIKELIHOOD THAT 4. Evidence that the product can be stored and used regulations, waste producers remain responsible for consultation with parties capable and/or likely to be with no worse environmental effects than the them under duty of care regulations. involved in the end-of-use management, such as the COSTS HAVE BEEN material it replaces. removal and resources sectors as well as offshore Developing the required end-of-use infrastructure in wind OEMs, to investigate potential for component There are many challenges with these procedures such the UK is subject to planning regulations (in England reuse, repurposing, repair and remanufacturing. SIGNIFICANTLY as the subjectivity in interpretation and the forced and Wales under the Localism Act 201132) and likely When these solutions are not suitable, recycling, processing of materials using environmentally costly will be subject to guidance set out in the Green Book33. incineration, disposal and landfill solutions can be UNDERESTIMATED. means, along with the end-of-waste panel that handles This will take time, which has to be factored in, to get detailed as a means of last resort. This information applications being unavailable for extended periods. UK infrastructure in place. 16 17

Figure 3. Global Carbon Composite FUTURE MARKET Demand in 201839 OPPORTUNITY Wind Energy Aerospace

24% 23%

This report summarises previous and current projects underway in the UK Automotive and globally to develop a blade recycling solution for wind turbines. As Sports Goods 10% already mentioned, a flotilla of new UK-based projects, initiated by the wind 13% Construction industry, has come online in the past year. Many more have been underway 4% in countries such as Spain, Denmark and the Netherlands for some time. Pressure Vessels

8% Marine 2%

At present, there are few UK companies extend the UK’s current job creation GLOBAL FORECAST Other Moulding Compound actively pursuing this opportunity. targets (60,000 direct and indirect FOR WIND FARM Stand-out amongst them, Scotland’s jobs by 2030) by an additional 5,000 4% 12% Renewable Parts, is a fast-growing jobs. By adding more advanced DECOMMISSIONING enterprise focussed upon component circular economy approaches (reuse, refurbishing and reuse that is now remanufacturing, refurbishment, etc.) Today, 2.5 million tonnes of composite expanding its operations into larger these targets could be increased by material are in use in the wind energy facilities to meet growing demand. at least 20,000 jobs by 2030. sector globally2. It is estimated that there are 12-15 tonnes of glass fibre Aside from a few trailblazers, there is Figure 4. reinforced plastic per MW of power37. low awareness amongst the UK supply Global Carbon Fibre Demand Glass fibre reinforced plastic (GFRP) 39 chain of the economic opportunity that by Sales (£million) in 2018 represents the majority of the USD 75 blade recycling, and the broader drive billion global market for composites. towards a circular economy in the wind In Europe alone, over one million sector brings. The University of Leeds, tonnes are produced annually, with a contributor to the report, estimates the construction, infrastructure and Other Wind Energy that if we can invest now in the birth transport sectors accounting for of a circular economy sector, the UK 193 772 almost 70% of that figure38. can extend its wind sector job creation targets by at least a third. When it comes to carbon fibre Moulding Compound reinforced plastic (CFRP), the global Sports Goods This assertion is supported by research 541 demand has tripled in the past decade from the Green Alliance and WRAP 1,313 (2010 – 2020) to around 160,000 (2015) that focussed upon the UK Marine tonnes38. Wind energy now represents waste sector. They estimated that the biggest sector with 24% of the 193 without new initiatives, 31,000 jobs Pressure Vessels global demand for this material, just could potentially be created in that Construction surpassing the aerospace (23%), sports 541 sector, in the coming years (relying (13%) and automotive (10%) sectors. upon energy from waste and landfill). 386 In terms of value, however, the wind If we add job creation based upon industry represents only 4% of the recycling development, that increases Automotive Aerospace global market (at £772 million) due to to 205,000 new UK jobs. Even better, 1,160 14,000 the use of low-cost, and often lower if we develop reuse and repair of quality, carbon fibres (see Figures 3 products and components, we can and 4)39. increase this projection to 517,000 new and higher value UK jobs. In the UK, current landfilling rates are 35% for CFRP and 67% for GFRP, out The report’s authors conclude that of which only 20% of CF and 13% of GF the creation of a blade recycling are recycled and 2% of CF and 6% of segment of the wind economy could 18 19

Figure 5. Figure 6. Number of Articles Published on Carbon and Glass In-Use Fibre Reinforced Plastic (FRP) Blade Mass and All Source Fibre Reinforced 1989-201940 End-of-life FRP Recycling Capacity Gap in the UK2

600,000 120 — Annual All Source EoL FRP Waste (5-7.5% Growth p.a.) 100 500,000 — Carbon Fibre 80 — Annual All Source FRP Waste Recovery (20% Growth p.a.) — Glass Fibre 400,000 60 — Cumulative Installed On/ Offshore FRP Blade Mass 40 300,000

Documents published Known FRP waste recovery gap (blue zone) of -90% in 2018, optimistically 20 reducing to -62% by 2030, i.e. prior to significant tranche of blade disposals 200,000

0 (t) Polymer Reinforced Fibre 2011 1989 1995 2017 2013 2012 2015 2018 2016 2019 2014 2001 2010 2007 2003 2002 2005 2008 2006 2009 2004 2000 100,000 Year

0

GF are reprocessed. Recycling even 20% of UK GF and 2013 2012 2018 2016 2014 2010 2022 2028 2026 2024 2030 UK FORECAST FOR WIND 2020 CF would be able to generate millions or even billions of pounds depending on the end product40. FARM DECOMMISSIONING

This is a topic of interest for materials researchers, As of 2019, there was a total of 24GW of wind capacity circular economy and environmental impact studies Figure 7. installed in the UK, 10GW of which was offshore41 as well as for individual industries (aerospace, marine, Offshore Wind Farm Decommissioning Projections (25-year representing nearly half of Europe’s installed offshore 45 wind energy, oil and gas, etc) as evidenced by the lifecycle - UK), an analysis of data from 4C Offshore wind capacity of 22GW and a third of the operational increasing number of papers on the topic (Figure 29GW offshore globally2. If the turbines that are currently 5). All of this research is complimented by projects being installed offshore are included, the capacity grows 500 established by companies and government institutions by 13GW. Onshore there are 13.6GW installed. in order to develop a cost-effective environmental Windfarm status solution for composite end of life, many of which Overall, there are 2,555 turbines and approximately 7,655 Consent Application Submitted will be discussed in this report. blades installed in UK waters, while onshore there are Consent Authorised 400 95 8,625 commercial turbines with 25,875 blades2. Figure 6 Fully Commissioned The two largest sectors (wind and aerospace) have shows the cumulative mass of all composite wind turbine Pre-Construction the opportunity to develop a new type of supply chain blades installed onshore and offshore in the UK as well as Under Construction targeting reclaimed fibres from composites. Industries the projections for the years to come. Assuming 20 years 85 like sports goods have low retrieval rates of used of operation, the number of wind turbines and blades 300 goods; firstly, because they are consumer goods, and that will be expected to be decommissioned can be secondly, because they contain small quantities of calculated and is presented in Figure 7. composites. Wind and aerospace, on the other hand are comprised of large quantities per product and, in It should be noted that these predictions are for 200 addition, the assets are managed by a small number wind turbine blade waste and do not include other

of companies (compared to the millions of individual components that are also often made of composites Number of Turbines consumers of sports equipment, for example). This (such as nacelle covers and rotor hub nose cones). allows for relatively easy predictions of the volume 100 of composites that will be disposed of in upcoming In 2018-2019 only 10% of all fibre reinforced plastic waste 209 years, which will encourage the supply chain to was diverted from landfill. Optimistic estimates suggest develop new products which reuse blades or use this number can increase by 20% per annum. However, by 2030 this would still leave a gap of 67% of all waste recyclates of the blades. 60 30 25 79 206 51 81 480 135 284 104 367 258 102 409 72 121 300 2 that would go to landfill . 0 2035 2084 2045 2030 2050 20 21

Figure 8. GLOBAL FORECAST FOR WIND Global Onshore Wind Capacity44 FARM DECOMMISSIONING

In 2019, there were 29.1GW of offshore wind power installed globally. By 2050, it is predicted that 85GW LIFE EXTENSION Italy Rest of the World of this wind farm capacity will be decommissioned, adding up to 325,000 blades. It should be noted that DOES NOT SOLVE 2% 16% this is a maximum estimate as it does not account for THE PROBLEM OF Canada the possibility for life extension or repowering and PR China 2% assumes that wind farms will be decommissioned BLADE DISPOSAL, 37% at the end of their operating life of 25 years. UK IT MERELY DELAYS Europe is the largest market (75% of all offshore 2% USA wind), followed by China, Taiwan and Vietnam42. North DECOMMISSIONING Brazil 621 GW 17% America currently operates only 30MW although this FOR A FEW YEARS number is expected to grow in the following years. 3% AND WILL SLIGHTLY Germany Overall, the top five countries by installed capacity are France UK, Germany, China, Denmark and Belgium. Onshore, REDUCE THE 9% there are more than 600GW installed. Out of those, 3% 230GW are in China and 106GW in the USA, followed STEEPNESS IN Spain India by India, Spain and Sweden42 (Figures 8 and 9). THE RATE OF THE 4% 6% As growth in the coming years is expected to increase (Figure 10), it is time to start thinking about what COMPOSITE happens at the end of life of materials that make up WASTE CURVE. wind turbines.

Figure 9. Figure 10. Global Offshore Rate of Wind Turbine Installation CAGR = Compound Annual Growth Rate Wind Capacity45 Globally (GW installed per year)42

CAGR +9% — Offshore CAGR -3% 63.8 — Onshore 3.4 60.4 Belgium Rest of the World 54.9 6.1 CAGR 53.5 +22% 51.7 2.2 50.7 4% 8% 4.5 1.6 4.4 45.0 Denmark 40.6 1.2 38.5 39.1 6% 0.9 36.0 0.6 0.9 1.5 PR China UK 29.1 GW 26.9 23% 33% 0.4 20.3 0.3 14.7 11.5 0.1 8.1 8.2 6.5 7.3 0.1 03 0.1 Germany 0.1 0.2 26% 6.4 7.1 7.9 8.1 11.4 14.6 20 26.5 37.9 38.2 39.8 43.9 34.5 50.2 60.4 52.7 49.0 46.3 54.2 2011 2017 2013 2012 2015 2018 2016 2019 2014 2001 2010 2007 2003 2002 2005 2008 2006 2009 2004

Share of offshore 1% 3% 5% 9% 22 23

Figure 11. Figure 12. Global projections for offshore wind turbine Global projections for onshore wind turbine decommissioning up to 205045 decommissioning up to 205045

90 1,300

1,200 80 1,100 70 1,000

60 900 800 50 700

40 600 500 30 400 Capacity (GW) Cuumultative 20 300

200 10 100

0 0 2031 2021 2041 2037 2027 2033 2023 2032 2022 2035 2038 2025 2028 2039 2036 2026 2029 2047 2024 2034 2043 2042 2045 2048 2030 2049 2020 2046 2050 2044 2040 2031 2021 2041 2037 2027 2033 2023 2032 2022 2035 2038 2025 2028 2039 2036 2026 2029 2047 2024 2034 2043 2042 2045 2048 2030 2049 2020 2046 2050 2044 2040

China Germany Denmark Netherlands Japan China Brazil Spain Norway South Korea Sweden UK Spain Belgium Portugal South Korea Italy France USA Netherlands Ireland Taiwan France USA Norway Finland Ireland Canada Germany Denmark Portugal Other Japan UK India Belgium Finland Vietnam Poland

Current decommissioning costs are estimated to be in waste curve. Making use of this delay in decommissioning the region of USD 223,000 - 668,000 per MW43. Again by developing promising reprocessing technologies assuming 20 years of operation, globally the rate at is crucial to increase recycling efficiency rates and to which wind farms are decommissioned and the rate at produce higher quality recyclates. which landfills fill with wind turbine blades is only going Over the next 30 years, global wind energy capacity is to grow if recycling and reusing technology, as well as expected to grow as discussed. However, assuming an the supply chain, is not advanced.. operational life span of 20 years, wind farms that are While lifetime extension offers a short-term alternative installed over the next 10 years will be decommissioned to decommissioning, extending the operational life of by 2050. Figures 11 and 12 show the projected capacity a wind farm (say, for up to 10 years) will depend upon of onshore and offshore wind power that is anticipated having a detailed assessment of the remaining useful to be decommissioned by 2050 based on the current life, environmental conditions, reliable monitoring of the consent agreements, planning applications and systems as well as overall operations and maintenance government targets that have been declared. These costs and expectations over the life of the wind farm. estimates do not consider the possibility of life extension There are no clear statistics on how many wind farm and repowering and assumes that windfarms will be owners will pursue this option. Furthermore, life discontinued at the end of their operating life of 25 years. extension does not solve the problem of blade disposal, it merely delays decommissioning for a few years and will slightly reduce the steepness in the rate of the composite 24 25 CURRENT APPROXIMATELY METHODS 60% OF WASTE OF BLADE FIBRE REINFORCED DISPOSAL PLASTIC IS LANDFILLED,

Fibre-reinforced plastics (FRPs) are From an environmental point of view, the a combination of plastic resins, glass, material offers significant benefits in the use-phase of a product because it is light, WHILE ANOTHER carbon and other fibres. There are strong and long-lasting. For example, it can reduce the weight of vehicles, cutting their fuel two main forms of plastic resins: consumption and thus their greenhouse-gas thermosets, which form an irreversible emissions. Fibre reinforced plastic is also vital SIGNIFICANT for the ever-larger blades of wind turbines, as solid polymer and are most commonly blades made from steel would be incredibly used in the manufacture of wind turbine heavy, less efficient and very expensive. blades, and thermoplastics, which At the end of their lives, they have proven PORTION OF IT IS difficult and costly to reclaim and reprocess. can be remelted and recycled. Fibre To fully satisfy the sector’s future growth reinforced composites are used in plans and sustainability goals, finding the right solution for recycling them is becoming INCINERATED FOR numerous applications such as vehicle imperative, especially as the first generation of wind farms are starting to reach the end of components, doors, bathtubs and wind their 25-year lifecycles. turbine blades. Approximately 60% of waste fibre reinforced ENERGY RECOVERY plastic is landfilled, while another significant portion of it is incinerated for energy recovery as heat. Where it is recycled, the reclamation techniques mean that it can only be used for AS HEAT. lower value applications – such as short fibre reinforcement or filler in new composite materials – limiting the economic case for using recycled materials. This is especially relevant for glass fibre reinforced plastics, as the low price of virgin glass fibres (£2-3/kg) does not incentivise the use of recycled glass fibres that may be a higher price and lower quality. Addressing these issues to strengthen the business case is a key aspect of establishing a functioning supply chain for recycled glass fibre46. 26 27

LANDFILL THERMAL MECHANICAL MECHANICAL MECHANICAL RECYCLING RECYCLING RECYCLING TO RECYCLING WITH Landfill used to be the most The European Waste Framework FINE FILLER FIBRE RETENTION economic form of disposal for Directive (2008/98/EC) established Thermal recycling involves the There are two main methods for many municipal solid wastes, the basic principle that the ‘polluter incineration of composites to mechanical recycling where the Glass reinforced plastic can be Glass reinforced plastic can be with many negative environmental pays’, known as extended producer reclaim the fibres for reuse. end material can either be in the ground to a fine filler, and this ground to a lesser degree, leaving impacts. These could include responsibility. This requires EU Pyrolysis of 500- 600°C breaks the form of powdered material or is done in-house together with bundles of fibres that have fires and explosions, vegetation Member States to apply the waste polymer down to components of short fibres. The main advantages manufacturing waste in some reinforcing properties. This uses damage, potential health management hierarchy: Prevention, wax, oil, char and gas. The oil and of this method are the low cost cases. However, it is not generally less energy and provides a more hazards, unpleasant odours, Re-use, Recycling, Recovery, wax are high in calorific content for recycling and the low energy economical since the energy input valuable product than fine filler. landfill settlement, ground water Disposal. Article 11.2 stipulates which, when reclaimed through the requirements, in addition to the is not viable for grinding a filler This is done in-house to a small pollution, air pollution, and global that “by 2020 a minimum of 70% pyrolysis process, can be reused fact that no hazardous fluids are that would only replace a low value degree, but there is potential for warming47. The landfill tax in (by weight) of non-hazardous to produce thermal energy. The released during the process (as product such as calcium carbonate. higher volume applications in England is currently £94.15 per construction and demolition gasses produced are hydrogen, long precautions are taken to the UK, such as in infrastructure tonne (2020-2021 rate), however, waste… shall be prepared for Mulching involves regrinding the methane, ethane and propane prevent the release of fine dust products with recycled mixed including the cost of gate fees and re-use, recycled or undergo other composite down to suitable size which can be fed back into the where employees are present). plastics48. transportation, the total cost to material recovery”50. plant furnace to fuel the process. However, the end material has to be used as filler material in new landfill waste is typically £130 Any gases or particulates that significantly lower value due products. This can happen through A significant barrier for further When blades are removed to £140 per tonne48. cannot be reused within the system to the reduction in mechanical cutting, grinding or chipping application of this process is from a wind turbine during are passed through a scrubber to properties52. As shorter fibres the material. In this process, the the provenance of material and Although landfill tax is not expected decommissioning or repowering, remove harmful elements before have lower mechanical properties, continuous fibres are broken therefore the expected or known to rise dramatically, Germany, they can require specialist vehicles, being released into the atmosphere. the real commercial value lies in down into smaller fragments and quality of the recyclate. Currently, Scotland, Wales and several other if transporting the structure as a The fibres are recovered for reuse; subsequent reprocessing of the lose their ability to provide high there are ongoing projects in the European countries have already whole, or they must be cut into however, the mechanical strength fibres into products such as matts durability and stiffness53. aerospace industry for recycling begun to ban or severely limit the manageable sections. Both options can be severely reduced by the or pellets. composite prepreg waste offcuts landfill of wind turbine blades48,49. can be costly, with the process of pyrolysis process. from the manufacturing process. Their materials can, and often cutting larger and strong blades The aviation industry’s health and are, considered as recyclable and requiring sizeable machinery safety regulations require high- there are concerns about their such as vehicle mounted wire or quality materials, but these offcuts environmental impacts due to diamond-wire saws similar to those can be used as they have not the associated carbon emissions used in quarries. It has been noted been stressed in operation. For during decomposition. By 2030, the that there are so few options to mechanical recycling with fibre European Commission’s Circular recycle wind turbine blades in the retention, it is of great importance Economy Package seeks to reduce USA that the vast majority to be able to trace the quality the amount of municipal waste of blades are taken to landfill or of the original source in order that can go to landfill to 10% by long-term storage facilities51. to ensure quality and strength increasing the rate of recycling48. of the reprocessed materials. Certification methods and bodies could play a crucial role in enabling this technology and establishing methodologies for reprocessing composite. 28 29 COMPOSITES IT IS DIFFICULT TO MAKE AN ECONOMIC SECTOR BY SECTOR CASE TO BUILD A RECYCLING BUSINESS

Composite recycling is a huge The following sections provide a brief OR SUPPLY CHAIN BASED cross-sector challenge and is not overview of the current composite recycling and disposal methods used EXCLUSIVELY ON THE solely an area of concern for the across other industries. wind industry. It is expected that the waste produced from the wind AEROSPACE WIND TURBINE BLADE industry will account for only 10% of the total estimated thermoset Among the first uses of modern WASTE STREAM. composite materials in the aerospace composite waste in Europe industry was in the late seventies when by 202552. With this relatively boron-reinforced epoxy composite was low volume and low quality of used for the skins of the empennages of the U.S. F14 and F15 fighters. production materials, it is difficult In and space product applications, the weight Due to the current global coronavirus pandemic these driven not just by the potential economic benefits, but to make an economic case to build of structures is a critical parameter in determining numbers are now likely to be considerably higher as also by government research incentives, and by society’s a recycling business or supply performance, fuel economy, and therefore lower airlines accelerate their retirements59. changing expectations. Studies have reported that the operating costs. The need for lowest possible structural cost of manufacturing virgin carbon fibre was around USD The common practice over many years has been to chain based exclusively on the weight led to development of high-performance 15 -30 per pound in 2011, while only USD 8-12 per pound remove usable parts from retired aircraft60 to be re- composites initially only for secondary aircraft structure, is needed for recycling. Numerous research projects are wind turbine blade waste stream. manufactured and reused as spares in younger aircraft but as knowledge and development of the materials seeking to gain more value from recyclates, particularly of the same type. The largest portion of recycled aircraft It is therefore essential to engage improved, their use in primary structure such as using chemical and thermal processes such as pyrolysis materials consists of aluminium, titanium, nickel-based wings and fuselages increased. The global aerospace and fluidised bed process for carbon fibre recovery. actively with all the composite- superalloys, stainless steel and electrical components composites market size is projected to grow from USD (about 60%). The remaining ‘non-recyclable’ aircraft Recycling of aircraft is currently not regulated by using sectors, manufacturers and 23.8 billion in 2020 to USD 41.4 billion by 2025, at a have been stored beside airports (or in deserts around legislation. The European Waste Framework Directive compound annual growth rate (CAGR) of 11.7% during the globe up until a few years ago) and in aircraft (2008/98/EC) is the closest applicable guidance and sets authorities to develop cost-effective the forecast period54. 61 and sustainable economic and graveyards . out the basic concepts and definitions related to waste The significant use of composite material in a management. It requires EU Member States to apply The number of stored aircraft on landfill sites has environmental solutions and strong commercial aircraft was by in 1983 in the rudder the waste management hierarchy of Prevention, Reuse, become a greater issue now that there are fewer of the A300 and A310, and then in 1985 in the vertical Recycling, Recovery. In anticipation of future legislation, markets for old models, particularly since previous material value chains. tail fin. To date, composite materials constitute up to the International Civil Aviation Organization (ICAO) and demand markets such as Indonesia, China and Russia 50% of most modern civil and defence aircrafts, with the Aircraft Fleet Recycling Association (AFRA) together have introduced import restrictions for used aircraft average weight savings of up to 20%55,56. with industry members62 have formed partnerships to over 10-20 years of age. The few that have been re- develop a best practice for end-of-life aircraft63, but purposed have become water bombers to fight wildfires, The average lifespan of a civil aircraft is 25-28 years challenges remain in terms of a lack of commercially viable 57 atmospheric aircraft, private jets, props for the film old , and 30-40 years for freight aircraft. Aircrafts are composite recycling technologies and market demand. retired when they become uneconomical to operate industry and hostel accommodation. due to higher costs of maintenance, overhaul or fuel Composite from the aerospace industry can be consumption. It has been reported that approximately divided into two categories: wastes generated during 9,526 passenger fleets and 785 cargo fleets will have the manufacturing process and parts from end-of-life been retired worldwide between 2017 and 202758. aircraft. Composite recycling is a growing consideration, 30 31

A COMBINATION OF LEGISLATION AND BUSINESS OPPORTUNITY HAS SPARKED SEVERAL WASTE MARINE

In the last 15 years, the industry has picked up pace REDUCTION AND RECYCLING The lightweight strength and durability in leading initiatives to develop chemical and thermal of glass fibre reinforced plastic was recycling technologies for composites. Boeing and Airbus, transformative for the marine industry two of the world’s largest aircraft manufacturers, have been DEVELOPMENTS ACROSS leading much of the research into composite recycling in the late 1950s, enabling the mass over the past few years. Boeing, with its industry partners production and sale of small, streamlined in AFRA, Airbus and PAMELA (Process for Advanced leisure boats. THE AUTOMOTIVE INDUSTRY. Management of End-of-Life Aircraft), is championing R&D to advance pyrolysis for composite recycling. Unfortunately, as vessels built in these early decades reach the end of their life, solutions for their safe retirement are In 2018, Boeing announced a partnership with British- required. Some of the more common practices for disposal based ELG, a leading international composite recycling have been to sink them by opening drainage holes, drilling firm, to reclaim carbon fibres from production at 11 and shooting holes in the hull, burying, cutting to pieces Boeing manufacturing sites using pyrolysis. The project for landfill, grinding for use as filler in concrete, or creating claims to have recovered 380,000 lb (172,000 kg) of garden features. carbon fibre from cured and uncured waste that was to AUTOMOTIVE be sold to other sectors (e.g. automotive and electronics The challenge remains to find good solutions for the firms) or used to build several prototype aircraft interior volume of vessels that have reached the end of their The automotive industry is one of the is produced during the manufacturing stage, where it components. When the project is expanded to the Boeing functional life or have become damaged, such as the is then used in stitched, non-wovens, car seats and roof facilities, it is estimated that it will recover around three 63,000 boats in the Caribbean that were damaged or largest sectors to use fibre reinforced structures (such as in the BMW i3 and i8). In total, 10% times as much carbon fibre and will help the company destroyed by hurricanes Irma and Harvey in 201765. As plastics in manufacturing, thanks to of this material used in the BMW i-series comes from reduce its total solid wastes by up to 20% by 2025. most boats currently end up in landfill or abandoned, there properties that make vehicles lighter, recycled carbon. Utilising recycled composites can reduce are concerns that they can present physical, navigational 64 stronger and more fuel efficient. the overall weight of cars by replacing aluminium and In 2020, ELG Carbon Fibre Ltd formed a collaborative and environmental hazards as they eventually degrade into steel in non-structural parts of the vehicle. Short fibres, for partnership with Belgium recycling start-up Aerocircular local ecosystems. Researchers have begun to investigate They can also make cars safer as the energy absorption example, can be used to reinforce thermoplastic matrices in order to establish a recycling scheme for aircraft the potential impacts these abandoned vessels could of thermoplastic composites is 7-8 times higher than that through injection moulding, with the resultant composite composite waste streams through a process expected to have on marine environments. Abandoned vessels may of steel. In addition, the sector has an extensive number 2 used as interior panels and other low load bearing save 20 tons of Global Warming Potential CO eq (carbon contribute to a loss of habitat, pose an entrapment risk for of regulations and legislation concerning the end of life of components. The short fibre reinforced composite also dioxide equivalent) at only 1/10th of the energy required wildlife, and can act as a local source of contamination66. vehicles. The End-of Life Vehicle Directive (ELV, 2000/53/ improves crashworthiness69. for producing virgin carbon fibre. EC) set targets that 85% (by weight) of vehicles must be In 2016, concerns were raised to the London Convention reused or recycled, and 95% reused, recycled or recovered A combination of legislation and business opportunity and London Protocol (LC/LP) governing bodies about (‘recovered’ here means burnt for energy recovery)48. has sparked several waste reduction and recycling the end-of-life management of vessels made from fibre developments across the automotive industry. In 2012, reinforced plastics. As a result, the International Maritime The Chinese government is also introducing legislation for example Boeing and BMW signed a collaboration IN THE LAST 15 YEARS, THE Organization (IMO) commissioned a study that reviewed on vehicle end of life. The new legislation targets agreement to participate in joint research for carbon fibre AEROSPACE INDUSTRY HAS current options for the disposal and recycling of boats the scrapping of vehicles and aims to improve the recycling70. Toyota and Toray Industries (a manufacturer of made from this material and to advise that further work standardisation practices. All recycling enterprises will be PICKED UP PACE IN LEADING carbon fibre) announced the development of a solvolysis is required67. The study found that while financially required to upload information regarding gearbox, engines test plant in 201671. There are also multiple projects that INITIATIVES TO DEVELOP viable options for recycling are limited, research is and chassis, such as serial numbers and models. This will focus on specific car products that could be developed ongoing into pyrolysis and solvolysis for the separation enable the tracking of materials and create an opportunity CHEMICAL AND THERMAL from recycled composites. In the FiberEUse project, of resins and fibres for reuse. Manufacturing levies have for the development of a supply chain focussing upon car supports were manufactured using end-of-life fibre RECYCLING TECHNOLOGIES been suggested as one method of achieving financial recycling and reusing materials68. reinforced plastic. Another project with similar results is FOR COMPOSITES. sustainability in the disposal of reinforced plastic vessels An article from 2018 estimates that recovery of carbon RECOMP which recycles glass fibre reinforced plastic and and France will potentially trial a programme of charging fibres can be achieved at USD 5-15 per kilogram, uses a ground version in automotive compound moulding. users for disposal67. depending on the technology used and the plant capacity39. This accounts for up to half of the cost of virgin carbon fibres. Much carbon fibre reinforced plastic waste 32 33

IT IS EXPECTED TO BE 20-30 YEARS BEFORE THE CURRENTLY DEPLOYED COMPOSITE PIPES ARE OIL & GAS

Traditionally, the oil and gas industry fibre layers bonded to each other through a melt-fuse DECOMMISSIONED, SO AS has used carbon steel due to its general manufacturing process. This gives TCP higher performance low cost and availability throughout properties than RTP made from the same materials, making it suited to higher pressures and a greater YET THEIR END-OF-LIFE the hydrocarbon value-chain, from the temperature application. Fully qualified usage77 of TCP at construction of wells and rig systems to pressures exceeding 12,000psi and in water depths as low pipelines, storage tanks, and refineries. as 3,000m have been deployed in the past three years. In REUSE OR RECYCLING HAS A significant downside of carbon steel 2017, Petronas installed the world’s first pilot TCP Flowline in Malaysia for offshore hydrocarbon service. With this is its limited design life due to corrosion, pilot’s success, TCP solutions for hydrocarbon production, and the economic cost associated water, gas lift, and chemicals injection are expected to be NOT BECOME AN ISSUE FOR with repair, maintenance, and installed in West Africa, Australia, and the North Sea 78. corrosion monitoring. The underpinning advantages of composites over metallic IMMINENT RESOLUTION. Composite materials have been used in the oil and alloys is in providing: gas industry for three decades, though sparingly. • High strength-to-weight ratio enabling the use of The willingness of the industry to adopt composite smaller, less costly vessels for transporting equipment components has been directly related to the operational to drilling and production sites risks of the components considered. As a result, REUSE AND ALTERNATIVE USE OPTIONS OPPORTUNITIES FOR FUTURE DEPLOYMENT • Greater cost advantages when replacing expensive the industry has made greater progress in adopting REUSE AND RECYCLING CONSIDERATIONS composites, primarily glass fibre reinforced plastics, for corrosion-resistant metals such as copper-nickel Many offshore installations and subsea structures in less operation critical components in secondary structural alloys, duplex / super duplex stainless steel, titanium the Gulf of Mexico and the North Sea are approaching Traditionally, subsea tiebacks – where small fields are ‘tied applications such as grids and gratings, handrails, ladders, etc., that are used in offshore platforms for various decommissioning and would need to be repurposed or back’ to floating production facilities or platforms – have and flooring for offshore platforms72. More notable applications. Their resistance to corrosion helps in decommissioned. Most of these installations and their been developed in a bespoke way, with the technology adoption has been for lifeboats and vessels. improving reliability and safety and also leads to associated subsea structures contain very little composite designed specifically for each deployment and much of it lower life-cycle costs material, if any. Where there have been composite located topside. OGTC has initiated a programme called In the 1990s, there was a surge is the development of materials in recently decommissioned structures, these Tie-back-of-the Future80 which focusses upon developing composite materials for pipe applications. This led to the • Good thermal insulation, excellent damping, and have been secondary structural components that have a circular economy approach for subsea tie-back solutions development of reinforced thermoplastic pipe (RTP)73, fatigue performance been shredded and sent to landfill. For lifeboats and in marginal fields. Marginal field developments are generally typically consisting of a thermoplastic liner overwrapped • Greater design flexibility vessels, there is the option of re-purposing them as only expected to produce for four to five years. with unbonded aramid or glass fibre composites, then floating caravan homes, although this has often been coated with thermoplastic. RTP is suited to lower pressure A significant proportion of the cost of conventional subsea Challenges in commercialising new applications remain a impeded by the economic cost of repurposing and market and less demanding temperature applications with the tiebacks is due to flow assurance mitigations which may significant hindrance due to the absence of qualification demand. To date, lifeboat end-of-life options have tended distinct advantage of having a fast installation time, but demand high levels of insulation, chemical injection standards for specific design applications. This is to be crude, and generally involve shredding composite demand for its application has remained limited. systems and heat input. Composites offer important compromised further by significant lack of long-term structures and reducing them to fragments for landfill. performance data75. The market was set to reach an properties with regards to corrosion resistance, thermal With higher pressures and temperatures, deeper water, estimated USD 1.98 billion by 202179, this is still significantly In the future, flexible flowlines, umbilical and power cables insulation and weight reduction compared to traditional deeper wells and more corrosive environments, the past less than established markets in the aerospace, defence could readily be recovered by reverse reeling as part of steel components to mitigate some of the challenges decades have seen research and development activities in and automotive industries, and is now likely to decline a decommissioning programme. Such materials could associated with these costs. thermoplastic composites (TCP)74 for use in components due to the Covid-19 pandemic. It is expected to be 20-30 theoretically be reused but proving that the integrity of such as pipes75, umbilicals, flexible and floating risers, Several projects are currently exploring composites for years before the currently deployed composite pipes the composite components has not been compromised flowlines, jumpers, casings, tendons and downhole tools disassembly and reuse. If the equipment used to develop are decommissioned, so as yet their end-of-life reuse or during service life, as well as during the handling process, used for well drilling and interventions76. TCP consists of a them was designed to be mostly installed subsea and recycling has not become an issue for imminent resolution. may be difficult. similar set of materials to RTP but uses higher performing then recovered and reused three to four times, subsea thermoplastic resins such as polyetheretherketone tiebacks for small pools could be more economically (PEEK), and higher strength reinforcement such as carbon attractive. These options offer reduced cost on first use and suitability for reuse, resulting in greater cost savings and environmental benefits. 34 35

COMPARED TO OTHER SPORTS, THE LEISURE BOATS SECTOR HAS THE LARGEST VOLUME OF CONSTRUCTION SPORTS

Glass fibre reinforced plastic is There are multiple sports that utilise composites for their COMPOSITES WITHIN used extensively for many different light weight, excellent mechanical properties and easy manipulation into various shapes. Some of this equipment applications in the industry, both in includes but is not limited to: A SINGLE PRODUCT, domestic and commercial buildings. Its strength and insulative properties, as well • Tennis and badminton racquets as ready availability in large quantities • Golf clubs and hockey sticks MOST OF WHICH ARE and ease of installation, • Bikes make it an ideal product to use. • Skis and other plate-like structures DISPOSED OF IN LANDFILL It is thought the industrial production of glass fibre (snowboard, windsurf) products in the construction industry started as early as the 1930’s, with the process, and types of products • Boats produced, being refined ever since81. Existing uses OR ABANDONED. All of these products commonly use continuous fibres, 82 within the industry include : making them hard to recycle and turn into new sports 53 • Concrete reinforcing fibre equipment . Since most sports’ equipment is sold individually to customers and contains relatively small • Fibreglass (combined with a resin) for panels and amounts of carbon fibre, there are no national or industrial structures: these can be for waterproof external retrieval programmes that recycle them. There are many cladding and roofing, translucent panels, strong initiatives where sports equipment can be donated to storage tanks or linings of steel tanks and structural be refurbished, reused or used for spare parts, but they members to replace steel or wood generally have a limited catchment area and the volume DEFENCE that can be processed is far smaller than is necessary to • Composite rebar in place of steel address the issue of the waste produced each year. The defence sector uses composite In 2017, the European Defence Agency started a project for • Glass fibre insulation used for thermal and noise assessing the opportunities and constraints that could be A notable project is ReSurf which salvages old surfboards materials across many areas, some of insulation in floor, wall, and roof cavities encountered when applying circular economy principles as part of a community project for under-privileged which have been discussed in previous in the defence industry. Following the project, a roadmap children and Project Green Ball which recycles tennis balls Disposing of glass fibre waste materials is a challenge sections such as military aircraft, was established proposing actions and alternatives for within the construction industry. Resin products can be and runs local programmes and shops for bikes. There are helicopters and land vehicles. Additional areas that are not suitable for a full circular economy87. also multiple initiatives that turn skis into new furniture used as a fuel source to burn with the remaining fibres In 2019 the UK Ministry of Defence opened an innovation – Reeski, Green Mountain Ski Furniture and SnowSource applications that have not been being reused for applications such as concrete feedstock. challenge fund to encourage industry to develop General Store83. mentioned include body armour, arms Depending upon the composition of the product, other prototype systems for defence waste management within In the USA, the Snow Sports Recycling Program retrieves recycling options are available, such as using parts and ammunition and military shelters. a circular economy context88. In addition, the Dutch all ski equipment, shreds it, and sells it to manufacturers of the materials for textiles and aggregates. However, Ministry of Defence established circular principles to cut for the production of composite lumber and synthetic Fibre reinforced plastic is frequently used to build aircrafts this is not always possible, so landfill is the commonly used down waste from uniforms, helmets and other Personal 84 (turbine, propellers, deck, armament), submarines and alternative. cultured rocks . 89 offshore patrol vessels (hull, decks, propellers, sonar), Protective Equipment (PPE) . Compared to other sports, the leisure boats sector has main battle tanks and infantry battle vehicles (tank floor, No other information has been identified in the public the largest volume of composites within a single product, armour, internal navigation systems, ammunition), missiles domain for reuse and recycling in the defence sector and most of which are disposed of in landfill or abandoned. (sensors/seekers, frames) and many more86. none of the strategies identified are specifically applicable However, if there was a stronger economic case there to carbon and glass fibre reinforced plastics. would be potential to reclaim the fibres for reuse in boat manufacturing. The Rhode Island Fiberglass Vessel Recycling (RIFVR) Pilot Project retrieves used and abandoned boats, mulches the fiberglass and uses it as filler for cement production85. 36 37

REVIEW OF Figure 13. Recycling Stages: Reclamation COMPOSITE and Reprocessing RECYCLING Waste Reclamation Reprocessing Part manufacture METHODS composite using recyclate

Composites can be defined as two or more materials that when combined have superior properties than the individual materials alone. Typically, they are comprised of reinforcement material (fibres) encased within a matrix material (resin). The fibres can take on several different weave architectures, resulting in plies that can be layered up and positioned at different orientations to provide the resulting composite product with the optimum performance characteristics for the chosen application.

Composite materials are therefore often beneficial in RECLAMATION CARBON FIBRES high-performance applications that also require low mass. However, the symbiosis of fibres and resins, particularly in the case of thermosetting resins, makes the end- There are a range of different fibre reclamation processes of-life options for composites more difficult than their available for composite materials at varying technology HAVE A VERY HIGH metallic counterparts. Nevertheless, processes to recycle readiness levels (TRL), depending on the materials that are composite products are available and becoming an to be recycled. Generally, carbon fibres have a very high increasingly popular option. tolerance to heat and thermal degradation which allows them to be taken to very high temperatures90. This is less TOLERANCE TO There are generally two stages that make up composites so for glass fibres, which following exposure to elevated recycling: the reclamation stage and the reprocessing temperatures (upwards of 150°C) show significant stage (Figure 13). The reclamation stage involves reductions to mechanical properties between 20% and reclaiming material from the original composite to be 65%, with higher exposure temperatures generating used in a secondary application. In most composite 90,91 HEAT AND THERMAL greater levels of degradation . The resin system used recycling processes, this stage mainly concentrates on can also influence the recycling method chosen, with the reclaiming the high-value material from the composite main factor being whether the resin is thermoplastic or (the fibres), but some processes are also able to reclaim thermoset. resin components or energy that can power subsequent DEGRADATION, BUT processes. Once the fibres have been reclaimed, they Thermoplastics can be reheated and reformed due need an additional reprocessing stage to turn them to the reversible nature of the bonds that hold them into a format that enables them to be used in another together. Therefore, when considering consumable product. These recycling stages are discussed in more thermoplastics that are not combined with reinforcement, THIS IS LESS SO detail in the following sections. these are considered to be easily recyclable compared to thermosets. In reality, however, it is not that straightforward, as there are still challenges around separating and retrieving the resin from the fibres. In some FOR GLASS FIBRES. exceptional circumstances, larger composite panels may be suitable for softening and reforming, but this is highly 38 39

dependent on the geometry of both the primary and IT IS CRUCIAL secondary application and is therefore not commonplace. Thermosets on the other hand, form more permanent chemical crosslinks upon solidification, which once formed MECHANICAL FOR THE are irreversible, and thus often require extreme conditions GROWTH OF to break down. Whichever method is chosen, either the method itself, logistics of transport or the space restrictions of the COMPOSITES infrastructure (furnaces, reactors, grinders) generally lead to continuous fibre composites being reduced in length GRINDING CEMENT KILN CO-PROCESSING RECYCLING to shorter, discontinuous fibres. Considering mechanical properties are affected by fibre length, with longer fibres THAT producing higher mechanical properties, this reduction in A large-scale, low-cost option that A large-scale, low-cost option suitable for fibre length through recycling often leads to a reduction in produces powder for filler or reprocessing glass fibre reinforced plastics that allows APPLICATIONS the mechanical performance of the resulting material. It is at TRLs 9 (glass fibre) and 6 (carbon fibre) for energy recovery and production of therefore crucial, for the growth of composites recycling but low-level concerns around microplastic cement clinker; currently at TRL 9, but that applications for recyclate are sought in order to make pollution and dust remain. environmental and health concerns remain FOR THE use of the material as it becomes available. over dust and other potential pollutants. Mechanical recycling techniques predominantly refer In addition to this, fibre reclamation processes remove RECYCLATE to grinding of cured composite material, reducing it the fibre sizing (a thin homogenous coating applied to Already operating at commercial scale, cement co- down to a significantly finer material. This technique is the surface of fibres during manufacture), which greatly processing is seen as one of the most promising options a two-stage process. Firstly, the material is shredded to ARE SOUGHT affects the quality of the fibre and matrix adhesion. This for the end of life management of wind turbine blades. turn the composite into more manageable sized pieces. isn’t as much of an issue for carbon fibre as it is for glass This involves a slow speed cutting mill that reduces the Following the mechanical reclamation of glass fibre fibre, as the surface energy of carbon is similar to the original part into pieces that are approximately 50- waste, the composite particulate is mixed with other solid surface energy of the resin systems used (the closer the 100mm in size. Metal inserts can also be removed at this recovered fuel and fed into cement kilns. The organic better for good adhesion). Despite this, many potential stage92. Following this, a high-speed mill is used to grind content (resin, core materials, adhesive) burns and helps end users of recyclate prefer resized fibres to maximise the composite pieces into a finer material, with particles to fuel the process while the inorganic glass fibres provide the properties of the composite. Fibre sizing happens ranging from fibrous strands (up to 10mm in length), minerals (such as alumina-borosilicate) for the cement at a specific point in the production of virgin fibres, down to finer powders (less than 50 microns in size)92. clinker. This clinker is then used to produce cement. and currently isn’t directly re-creatable in the available The recyclate is then classified based upon its resulting recycling processes. This therefore presents an area While it could be argued that this processing method is size using cyclones and sieves. In this process there is no of opportunity for further development in composites not strictly recycling, as there is no prospect for reusing separation of the resin from the fibres, thus the resulting recycling in the future. the recyclate in a composite application, it does have some recyclate is a mixture of the two materials. advantages over incineration to recover Energy from Waste There are four main categories of reclamation for The recyclate can be used as a filler in other applications (EfW): composites recycling that sit at different technology if derived from thermoset composites, or re-extruded readiness levels (TRL) levels depending upon the materials • Lifecycle Analysis (LCA) has reported a 16% reduction for further processing if derived from thermoplastic to be recycled. These are summarised in Table 2 and in CO2 emissions compared to using sand to provide composites. There is also a growing interest, particularly in discussed in more detail in the following sections. silica to the kiln52. Germany, in using the recyclate from wind turbine blades in cement co-processing. While this technology is, strictly • There is also a reduction in the amount of coal, lignite speaking, recovery rather than recycling, its popularity and petcoke used in the process. means it is worthy of inclusion in this review. • Resins used in composites have a high calorific Table 2. Whilst this process can be used for all types of composite content. This can be undesirable for energy recovery The Technology Readiness Level waste, and is one of the cheapest recycling options, it from waste, as capacity is limited by energy release (TRL) of the Reclamation Processes is only available on a commercial scale for glass fibre According to Fibre Type52 rather than tonnage burned. reinforced polymer. It is not economically viable for polymers reinforced with carbon fibres due to the higher • The mineral content of the glass fibre reinforced value of the fibre, especially considering the low cost plastic, which falls as ash in energy recovery, is incorporated into the clinker. RECYCLING TRL CARBON TRL GLASS of other commercially available filler materials such as calcium carbonate and silica. As a result, processes that PROCESS FIBRE FIBRE Aside from potential issues arising from the release of allow for fibre and resin separation are preferred for pollutants and particulate matter, the major drawback of carbon fibres90. Mechanical 6 9 recycling blade waste via this method is that it is currently limited to glass fibre materials. Due to health and safety issues around the presence of unburned carbon fibres Thermal 9 5 in the clinker (similar to the situation with asbestos), the method cannot be used to process blades containing 93 Chemical 6 5 carbon fibre reinforced plastics . More recently, the move to bigger blades has increased the use of this material, effectively putting a time limit on the viability of co- Electrical 4 4 processing for wind turbine blade waste. 40 41 THERMAL

PYROLYSIS fibres can adversely affect the fibre-matrix interfacial separated by a cyclone. The gases from this process are demonstrate the potential of this technology for more bonding in post processing (decreasing resin wet-out fed to a high-temperature combustion chamber for full widescale use if further process development and scale-up and reducing mechanical properties), so its formation oxidation and energy recovery, producing a clean high- can be achieved. An energy intensive way of recovering oils is undesirable95. Therefore, a subsequent post-pyrolysis quality fibre with good mechanical properties92. treatment (oxidation in air between 450°C and 600°C) is from resins that is available at limited scale A benefit of the process is that it can be used to treat often required to obtain clean fibres90,91. This secondary and only at a relatively high cost; suitable mixed and contaminated materials including painted STEAM PYROLYSIS process can lead to further degradation of the fibres, so surfaces, foam cores and metal inserts. However, the for carbon fibre recovery (retaining up should be approached with caution81. The resulting fibre is fluidised bed process does not allow recovery of products to 90% of mechanical properties) but then chopped to create the final product. An energy intensive process at TRL 4 currently unsuitable for glass fibres due from the resin apart from gases, whereas traditional A UK-based company, ELG Carbon Fibre Ltd, is capable pyrolysis can enable recovery of oil containing potentially that yields high-quality carbon fibres to the lower quality of outputs. of pyrolysing carbon fibre in this manner from diverse valuable products. Furthermore, carbon fibres seem to (more than 90% of mechanical property feedstock, including different types of carbon fibre and become more damaged in this process in comparison to Thermal recycling techniques involve the use of high retention) but only at very small scale most thermoset resin systems. As a result, fibres reclaimed the traditional pyrolysis process, which has been attributed temperatures to break down the composite from both to date. from industrial processes generally present a distribution to abrasion by the fluidised sand90. In a study by the uncured manufacturing waste, and cured components90. of properties; however, they blend their products to University of Nottingham, carbon fibre showed a reduction Steam pyrolysis (or thermolysis) is a relatively new process The most studied and commercially available thermal minimise property variation within the material. ELG claim in its mechanical properties of 25% when pyrolysed at for composite materials, and thus it currently sits at a low recycling process is pyrolysis. This process allows for that the resulting mechanical properties of their recycled 550°C. This is a greater reduction than those previously Technology Readiness Level (TRL 4). A report generated reclamation of the fibres, fillers and inserts through carbon fibre are equivalent to approximately 90% of that reported for the traditional pyrolysis technique. Various by Alpha Recyclage Composites discusses the nature thermal degradation of the resin system. Due to the high of virgin fibres96. ELG was one of the first companies academic institutions are investigating ways to remedy of the technology with some promising initial results101. temperatures involved, pyrolysis is often only used on to pioneer this process, but there are now multiple fibre damage caused in the processing of glass fibres The process used superheated steam to remove epoxy carbon fibre composites, as they are less susceptible companies across the world that can also reclaim carbon using this method in order to increase its commercial resin (Hexcel HexFlow RTM-6) from carbon fibres. It was to thermal degradation at high temperatures. The fibre in this way. viability for glass fibre composites97,98,99. possible to remove high levels of resin (more than 99% by degradation point of glass fibre, however, is much weight) without any significant changes in the quality of lower, and similar to that of many of the resins used to carbon fibre that was reclaimed. manufacture composites. Therefore, it is not possible to thermally remove the resin without causing significant FLUIDISED BED PYROLYSIS MICROWAVE ASSISTED PYROLYSIS Furthermore, fibres showed minimal signs of surface heat damage to the glass fibres. These temperatures degradation in comparison to those recovered from cause changes to the crystalline structure, decrease fibre A high-cost and energy-intensive process Suitable only for carbon fibre-based traditional pyrolysis. This was indicated by the absence of diameter and cause surface cracks, all of which will reduce the pitting effect that is seen on fibres reclaimed using the the mechanical performance of the resulting glass fibre. currently available at limited scale; materials; high-cost and available at very traditional pyrolysis method. produces good-quality and clean carbon small scale; produces good-quality carbon Similar to mechanical grinding, the first stage is to shred fibres (up to 70-80% of mechanical fibres (at up to 75% of mechanical property Comparisons of mechanical properties between virgin the composite waste to reduce its size before entering fibre tows and those reclaimed from steam pyrolysis also the pyrolysis process. Pyrolysis processing parameters properties retained); currently at TRL 4 retention) and achieves lower energy yielded promising results. Values for tensile strength and have a significant impact on the physical state of the (glass fibre) and TRL 5 (carbon fibre). intensity than other thermal methods. elastic modulus were reported to be comparable between reclaimed fibres. These therefore need to be selected and the two, with the tensile strength reported as 136MPa This is a variation of the pyrolysis process that has only Microwave assisted pyrolysis is a relatively immature optimised to suit the materials going into the process and (in comparison to 141MPa in virgin fibres) and the elastic been achieved at large lab scale (Technology Readiness process in comparison to traditional pyrolysis, but it has the onward application. Typical processing temperatures modulus reported as 8.4GPa (in comparison to 8.9GPa in Level 4/5) and therefore has not yet been commercialised. shown some promise with cured carbon fibre/epoxy on are reported to lie anywhere between 350°C and 700°C virgin fibres). However, the authors acknowledged that 94 The University of Nottingham has conducted extensive an academic scale (Technology Readiness Level 4) at the depending on the resin system . The lower temperatures more tests are needed to validate these initially promising research in this area to recycle carbon fibre92, and more University of Nottingham90. This process uses microwaves are adapted more towards polyester resins, whereas results in addition to industrial feasibility studies101. The recently, the University of Strathclyde has conducted to heat the material in an inert atmosphere, which epoxies or thermoplastics like PEEK require higher effect of this process on glass fibres is currently unknown 90 similar work to extract glass fibre97. degrades the polymer into gases and oil. temperatures . Under these conditions, the resin breaks and warrants further research. down into lower molecular weight organic substances In this process, the shredded scrap composite is fed into The main advantage of this process is that it allows for (liquids and gases)92. The gases (typically CO , hydrogen, 2 a bed of silica sand which is fluidised by hot air. This acts targeted heating, making it fast and efficient. Furthermore, or methane) can be used as energy feedstock in the to heat the material quickly, and results in attrition of the this method heats the material from its core outwards, process itself, while the liquid (oil) can be reused as fuel resin through abrasion by the moving sand. Similar to further improving the speed of heat transfer and or chemical feedstock. Therefore, despite the high energy classical pyrolysis, a small amount of oxygen is required to efficiency. This means lower energy consumption, as well demand of high temperature processing, pyrolysis can minimise char formation. The operating temperatures are as providing environmental and cost benefits over other feed products back into the system, and is therefore a low typically between 450°C and 550°C, which are lower than processes. Tensile testing of the resulting fibres reclaimed waste process. It is also often a continuous process that typical pyrolysis conditions. At these temperatures, the from a carbon/epoxy composite indicated a reduction helps to improve its efficiency. thermosetting polymer volatilises and, once the polymer of 25% for tensile strength and 12% for tensile modulus100 A common side effect of pyrolysis is the formation of a has been removed, the fibres and any mineral fillers are in comparison to virgin fibres, which is comparable to solid char residue. The amount of char build-up on the released and carried away in the gas stream before being other recycling processes. These promising initial results 42 43 CHEMICAL

SOLVOLYSIS HIGH-TEMPERATURE, LOW TEMPERATURE, LOW HIGH-PRESSURE SOLVOLYSIS PRESSURE SOLVOLYSIS More developed for carbon fibres (at TRL 6); high cost and small-scale availability; an energy intensive process that Currently at TRL 4 with associated TRL4; produces good-quality and clean yields high-quality glass (up to 70% mechanical property high cost and limited availability; carbon fibre and epoxy monomers; retention) and carbon fibres (90%). produces good-quality and clean less energy intensive than the previous carbon fibres; environmental and safety entry but involves use of acids that are Chemical recycling methods involve treatment of the composite using heat and solvent to degrade the resin, allowing for reclamation of the fibres with concerns are its high energy intensity problematic to dispose of sustainably. no char formation. Solvolysis currently sits at Technology Readiness Level and the high-pressure corrosive nature Low temperature, low pressure solvolysis is generally 6, offering a wide range of processing possibilities using different solvents, of the procedure. carried out below 200°C and at atmospheric pressure. temperatures, pressures and catalysts. During the last decade this method Catalysts and additives are necessary to degrade the has been more intensively used to recycle composites, in particular carbon High pressure solvolysis using supercritical fluids has resin as the temperature is very low and stirring can also fibre reinforced polymers, as the recovery of carbon fibre has become of been investigated at an academic scale (Technology be necessary. The main advantage of this method is commercial interest, but it can also recover glass fibre and aramid from cured Readiness Level 4). Supercritical fluids display that it offers better control of the reactions and, as the or uncured material90. properties that are between those of gases and temperature is low, secondary reactions do not seem to liquids. They offer a range of advantageous properties occur. This enables higher recovery of epoxy monomers, In many cases, carbon fibres recovered through solvolysis retain that provide the ability to closely control the solvent but not necessarily the curing agent90. It is also therefore approximately 90% of the properties of virgin material as the carbon fibres properties and reaction rates through pressure likely to consume less energy than other solvolysis are not degraded by the process, and in this way, it is comparable to pyrolysis. manipulations. Water is a useful option because of processes. However, acids are used in the process, which For glass fibres, which possess a lower tolerance to high temperatures and its temperature and pressure dependent properties. can be dangerous as well as difficult to dispose of or acidic/alkaline conditions, the reduction in mechanical properties is greater. Depending on the conditions, it can support ionic, polar recycle90. This process has only been demonstrated on an In a study conducted by the University of Exeter, glass fibre and polyester non-ionic or free radical reactions, and can therefore be academic scale, and therefore is Technology Readiness composites exhibited significant reductions in tensile strength and failure described as an adjustable solvent. strain (up to 70%), however modulus did not appear to be significantly Level 4. affected by the water-based solvolysis process102. Under supercritical conditions, the most stable thermosets (epoxies) and thermoplastic (PEEK) resins Solvolysis has started to gain more attention as under the correct conditions can be fully degraded using solvents such as water, ELECTROCHEMICAL it offers the ability to recover matrix materials in another form, which is not methanol, ethanol, propanol, and acetone without the possible with processes such as pyrolysis. Another advantage compared to need for additional catalysts103. It does, however, require pyrolysis is that lower temperatures are generally necessary to degrade the specific and expensive reactors that can achieve high Low readiness for commercial use (TRL 4) resin. Solvolysis can also avoid the formation of char that contaminates the pressures and corrosion resistance90. This is a limiting at high-cost and small-scale availability; fibre surface and prevents good interaction between the recycled carbon factor on its widescale use, especially for lower value yields glass fibre of usable quality but is fibres and the matrix. However, fibres recovered from a solvolysis batch material such as glass fibre, but it has been reported to reactor require further processing to remove organic surface residue, which is produce good-quality, clean carbon fibres90. yet to overcome high inefficiency due to often a long and expensive procedure. This can add further time, energy and the energy use in its process. costs and is therefore one of the main drawbacks. Solvolysis also removes the sizing from the fibres, affecting the fibre/matrix interactions of resulting The High Voltage Fragmentation process was originally materials. developed for fracturing rocks to retrieve high-value minerals and crystals, such as gold excavation104, but Among the tested solvents, water appears to be the most used, sometimes has since gained interest on an academic scale with neat or with a co-solvent (alcoholic, phenolic, amine); others include composite materials. In this process, the material is placed methanol, ethanol and acetone. The process is usually executed between between two electrodes in an aqueous solution. A series 350°C and 500°C, which is lower than the general temperature range for of capacitors are used to generate up to 200kV pulses pyrolysis. The nature of the resin determines the temperatures and solvents that are administered rapidly and repetitively in order to needed for effective degradation: for example, polyester resins are generally weaken the resin material. The repetitive pulse fragments easier to solvolyse than epoxy resins and so require lower temperatures to the polymeric resin into smaller sizes and leads to ultimate be degraded. Often solvolysis is used with alkaline catalysts like sodium disintegration of the material104. This process is high hydroxide or potassium hydroxide, but less often with acidic catalysts. Acidic cost and energy intensive, sitting at a low Technology catalysts are used to degrade more resistant resins such as PEEK, or to Readiness Level (TRL 4)90. degrade epoxy resins at lower temperatures90. 44 45 REPROCESSING

Reprocessing stages take the reclaimed materials and turn them into secondary MILLED FIBRE CHOPPED FIBRE material to be used in another applications. This isn’t needed for mechanical grinding recycling processes as the ground material is used in its reclaimed form A well-established method for glass Conducted following pyrolysis or as a filler, but material from other recycling processes is in the form of a fibre ‘fluff’ fibre materials (TRL 9) and is under solvolysis; a well-established method for which requires post processing to ensure it can be reused. The typical forms of demonstration for carbon fibres (TRL 6); glass fibre materials (TRL 9) and at the recyclate that can be produced from reprocessing are illustrated in Table 3. These outputs are powder additives and fillers demonstration stage for carbon fibre are all commercially available products from companies such as ELG Carbon Fibre for electrical and thermal conductivity; materials (TRL 6); a low-cost process Ltd, with milled and chopped fibres also available from Procotex. Milled glass fibre produces microplastics and dust risks. that can be used to produce SMC/BMC, is also available from companies such as East Coast Fibreglass. These material prepreg tape and cement reinforcement; forms can be used in common composite manufacturing processes, such as resin Milled fibre is a product of mechanical grinding, and therefore comes in the form of a fine powder. This can pose a risk to workers handling infusion, injection moulding, press moulding and thermoplastic compounding. can then be incorporated as filler or reinforcement if dry fibres. derived from thermoset composites, or re-extruded and reprocessed if derived from a thermoplastic composite. Recycled fibres can also be chopped into consistent short Carbon is also a useful additive where enhanced thermal fibre lengths for use in alternative products. They typically and electrical conductivity are desirable; but, in most arise from taking the fibre fluff produced by pyrolysis and Table 3. solvolysis methods and then organising and chopping The Main Forms of Recyclate cases, it is not economical to use ground carbon fibre due to other options being available at a much lower cost. the resulting fibres. This allows them to be incorporated into randomly oriented discontinuous fibre materials such Whatever the incorporation method, it is important to as BMC and SMC. For example, ELG Carbon Fibre Ltd FIBRE TYPE IMAGE FIBRE LENGTH USES monitor the weight percent (wt%) of recyclate within the produces fibre lengths of 6-12mm. composition of the secondary material. This is because Milled fibre 80-100mm Additive/filler for the presence of the recyclate within the composition A potential downside is that failure to chop this material tailored electrical and down further can lead to inhomogeneous distribution of thermal conductivity acts to increase the viscosity of the resulting material. It can become extremely viscous and difficult to process the fibres, thus uneven thickness, which results in a lower 90 if the wt% is too high, and the resin does not uniformly fibre content and a higher void content . However, when impregnate the ground fibres with a possible knock-on processed correctly these chopped fibres can also be used 64 effect to the resultant properties. Due to the very limited to modify coatings or other thermoset resin systems . fibre length, materials incorporating ground fibre are not The properties of BMC using recycled fibres can be similar Chopped tows 6mm Thermoplastic compounding, suitable for use in structural applications. Alternatively, to virgin carbon fibre90, while recycled fibre SMCs have sheet moulding compounds the recyclate could also be used as an energy source (SMC) and bulk moulding comparable properties to virgin glass SMCs. Typically, 92 compounds (BMC) as it is resin rich with a high calorific value . The longer SMC and BMC materials are turned into products via Cement reinforcement fibres obtained from this process can also be used as Prepreg tapes compression moulding, but fibre loading should be reinforcement material in sheet moulding compounds considered in these cases as above a certain wt% the (SMC) and bulk moulding compounds (BMC) where short properties no longer improve and can begin to deteriorate. fibres are required. BMCs and SMCs using recycled fibres are beginning to Pellets 1mm - 1.5mm Injection moulding find applications in the automotive industry, where the (thermoplastic) ability to manufacture at high rates and high volumes is advantageous.

Non-woven mat 40 - 90mm Press moulding RTM Resin infusion Wet pressing Prepregs, semi-pregs and SMCs 46 47

Figure 14. Effect of Increasing Volume Stiffness Fraction on Resulting Mechanical Properties of Non-Woven Mats106 Strength

PELLETS A

45 220 A well-established method for carbon composite. The fibre was a T300 fibre supplied by Toray, fibre (TRL 9) and at demonstration level which was recycled by ELG before being converted into a 100gsm non-woven mat using a papermaking process at 40 200 for glass fibre materials (TRL 6); low-cost Technical Fibre Products Ltd. The non-woven mats were but not yet large-scale enough for wind collated with 200gsm resin film, MTM56-2FRB supplied industry requirements; currently used in by Cytec, and compression moulded at 120°C under 35 the injection moulding and over-moulding varying pressure between 2MPa and 14MPa, resulting in 180 of composite parts but with associated various fibre volume fractions ranging from 20% to 40%. To evaluate the mechanical performance of the composite, 30 risks of microplastic pollution and dust. tensile and flexural tests were performed on at least five 160 106 Recycled carbon fibre reinforced thermoplastic pellets are specimens of each fibre loading , with results shown in 25 intended as a low weight replacement for glass fibre filled Figure 14. thermoplastics, a low-cost replacement for virgin carbon It was established that the non-woven mat was successful 140 Tensile stiffness,Tensile GPa fibre filled materials, and as an alternative to aluminium in enhancing the tensile and flexural moduli of the 20 strength,Tensile MPa and magnesium castings. Current challenges with the composite as the fibre volume fraction increased from material have been achieving sufficient fibre length and 20% through to 40% (Figure 14). However, when analysing 120 loading, as well as ensuring the product is dust free. the strength, such linear correlation between modulus and 15 Work is ongoing to establish optimum fibre loading and fibre content only applied for fibre content up to 30%. mechanical properties. Beyond this, strength begins to drop again. The drop in 10 100 Currently, pellets are commonly used in the injection strength was attributed to degradation in fibre length moulding and over-moulding of composite parts. distribution and an increase in composite void content as 15 20 25 30 35 40 45 the fibre content increased. Processing techniques and resulting pellet products Fibre volume percent 105 have been investigated by Barnes . During this study, Research has also investigated how to fully utilise the fibre pellets were produced from recycled material that was reinforcement potential. It was established that the critical comparable to virgin carbon fibre material for compounds fibre length can be determined from the fibre radius, fibre with polypropylene and polyamide 6,6. They established ultimate tensile strength and composite shear strength B that a 10% loading of recycled carbon fibre provided the respectively106. 40 same mechanical properties as a 30% loading of glass fibres, allowing them to produce air inlet manifolds at a Thermoplastic matrix non-woven materials are also 340 15% weight reduction from the original product. available, such as ELG’s CARBISO™ hybrid. In this material, thermoplastic fibres are blended with recycled carbon 35 fibres, creating a mat that is suitable for compression NON-WOVEN MAT moulding applications. 300 30

At TRL 9 for both glass and carbon fibre Fibre alignment 260 materials; low-cost but requires scale- Fibre reclamation typically results in short carbon fibres, 25 up; can be used in processes of press making them well suited to direct moulding techniques moulding, resin infusion, wet pressing, such as compression moulding of BMC/SMC materials, 220 prepregs, semi-pregs and SMCs; carries dry or non-woven mats. Due to the discontinuity and random 20 Tensile stiffness,Tensile GPa fibre handling risk for workforce. orientation of the fibres, these products are typically strength,Tensile MPa inferior to the original products from which the materials Non-woven mats provide an easy way to handle reclaimed originated. To improve mechanical performance of 15 180 fibre as sheet material and can either be processed with recycled fibre composites, high levels of fibre alignment liquid resins or converted in to a prepreg material. This are needed to enable a higher fibre volume fraction. therefore makes them suitable for processes such as resin Previous academic research has looked at papermaking 10 140 infusion, resin transfer and compression moulding. techniques and centrifugal alignment107 of fibres, achieving 80% and 90% alignment levels respectively. One of the 15 20 25 30 35 40 45 Feasibility work has been conducted on using recycled most effective to date is the HiPerDiF method108. fibre in a non-woven mat form for a flame-retardant epoxy Fibre volume percent 48 49

REUSING THERMOSETS

TRL 8 - about to become commercially available for glass fibre reinforced plastics; The Re-Wind Project is specifically interested in Superuse Studios NL B.V. run multiple projects that concepts for reusing blades for different purposes repurpose blades as playgrounds, bike sheds, benches moderate cost but very limited number of and demonstrating a number of them. One of the first and other outdoor installations109. There are several other examples; repurposes blade sections for limitations is understanding the overall mechanical smaller projects and design studios that have utilised use in civil engineering and construction; properties of blades if they are used as structural blades in the making of benches or other furniture. has the lowest environmental impact of all components (bridge foundation, roof, electric pole). Depending on the solution, the end value of the product While wind turbine blades from the same wind farm are can be higher–in many cases, much higher–than a product methods reviewed. expected to have similar mechanical properties, this may made from standard materials (for example, a bookshelf Blades can be reused without changing their shape or not be the case for different wind farms and certainly made out of plywood can retail at a lower price than one grinding them. Figure 15 shows the cross-section of a not for different manufacturers. As a result, this could repurposed from a wind turbine blade section). blade that can be repurposed as a whole, for example increase the overall cost of the end product if additional as a cell tower or as noise barriers along highways and strength testing is required. Another challenge is to motorways. The blade can also be cut into sections (root, develop solutions that can easily be modified or scaled up aerofoil sections and shear webs) for use in different for larger blades. Furthermore, most of the solutions that applications. The root sections, depending upon the have been developed thus far do not offer the scalability diameter, can be used for quiet pods or storage tanks A required for the bulk demand of the future. among many other uses that take advantage of a blade’s rounded shape. The shear web is the only flat part on the blade and can be used for various components and even furnishings including window shutters, benches, tables and doors. Profiles of the blade can be used to create complete roof sections and structural features too.

According to the zero-waste hierarchy, reuse of blades (and other composite materials) is the next best option after lifetime extension. Reusing components allows for minimum processing, as the parts only require cutting into the required shapes and sizes, usually with an industrial diamond cutter, such as those used in quarrying. While a Root Transition region Airfoil Tip (circular (from circular cross-sections number of solutions have been identified and trialled for cross-sections) to airfoil cross- the reuse and repurposing of wind turbine blades, further sections) Cap Shell development is required to present this as a viable end-of- B life strategy. In addition, solutions are very specific to the available size of the blades (solutions for 25m blades are extremely different from reuse solutions for 100m blades). Figure 15. This will continue to be a challenge as blades grow in size. Wind Turbine Blade Cross Sections

Leading Shear Trailing edge web Edge 50 51

THE LOWER COST OF CARBON, GLASS AND ENVIRONMENTAL FABRIC RECYCLATES COMPARED TO VIRGIN IMPACT OF MATERIAL CEMENTS THE ECONOMIC CASE RECYCLING FOR RECYCLING.

A B 35,000

30,000 70 60

60 25,000 50

50 20,000 40 40 15,000 30

carbon fibres -eq./t 30 2 € /kg Cost Fabric € /kg Cost Fabric 10,000 20 20 CO kg

5,000 10 10

0 0 0 Virgin Carbon Fibre Aluminium ELG Carbon Fibre Virgin Recycled Virgin Recycled Production Recycling and Fibre Fibre Fibre Fibre Conversion Fabric Fabric

ELG also reports that the recycled material costs less Recycling processes are energy intensive, Figure 16. Figure 17. and therefore impart an environmental Global Warming Potential (GWP) of to produce than virgin material. This is the case for both Cost Comparison Between carbon and glass fibres, as well as fabric (Figure 17), Virgin Fibre and Recycled Fibre impact. It becomes an environmentally Recycled Carbon Fibre Compared 110 to Virgin Carbon Fibre110 demonstrating the economic potential of recyclate if for a) Fabric and b) Fibres viable solution only when the energy the appropriate applications can be sought. demanded is less than that of virgin material production.

Most studies on end-of-life environmental impact focus on carbon fibre reinforced plastic due to its higher economic value and ability to retain properties once recycled. ELG Carbon Fibre Ltd have presented results indicating that, despite the energy demand required for pyrolysis, the Global Warming Potential (GWP) of using recycled carbon fibres is significantly lower in comparison to using virgin carbon fibres (Figure 16). In addition to lowering GWP, utilising recyclate diverts the material away from landfill, and therefore abolishes the need to pay landfill costs as well as reducing the need to consume raw materials. 52 53

Figure 18. Energy Demand (in MJ/kg) for the Predominant Composite Reclamation Technologies101 THERE REMAIN

100 FUNDAMENTAL 21 – 91 90 80 CHALLENGES 70

60 50 IN MAKING 40 24 – 30 30

demand (MJ/kg) Energy AN ACCURATE 20 5 – 10 10 0.1 – 4.8 0 LIFE CYCLE Chemical Pyrolysis Microwave Mechanical Pyrolysis ASSESSMENT

The reported energy demand, and thus environmental out of the two. Lee et al, demonstrated that the energy OF RECYCLING impact, of recycling techniques varies widely depending footprint of solvolysis was approximately six times lower upon their processing conditions (Figure 18)110. As than that of pyrolysis, and that the greenhouse gas illustrated, mechanical processes have been reported emissions were five times less113. Pyrolysis has also been to have the lowest energy demand, while solvolysis reported to produce carbon dioxide and methane which TECHNIQUES techniques span the largest range, reaching the highest contribute to its greenhouse gas emissions. energy demand. This is due to the high temperatures, and It is important to note that literature entries for sometimes high-pressure equipment, needed to perform composites recycling are typically ‘one offs’ for a very solvolysis. It should be noted that variation in these results specific set of processing parameters and assumptions will also be influenced by the differences in scale of the AND SIGNIFICANT that are often reported with limited detail. This makes studies that produced them110. For mechanical grinding, the values generated extremely varied and therefore the major contribution comes from energy consumption difficult to translate across different composite products. for powering granulators at room temperature110,111 and the Furthermore, these results are predominantly focussed Primary Energy Demand (PED) can be affected by the RESEARCH IS upon Primary Energy Demand and there are other processing rate. It was established by Shuaib et al, that environmental impacts that should be assessed through higher processing rates led to a more efficient process by Life Cycle Assessment (LCA), but this research is displaying lower energy demand/kg/hour111. currently scarce. High pressures are not needed for pyrolysis, just high NEEDED INTO THEIR Our conclusion is that there remain fundamental temperature, which is the likely reason for a lower challenges in making an accurate Life Cycle recorded environmental impact than solvolysis (Figure 18). Assessment of the techniques discussed, and there Microwave pyrolysis requires a lower temperature, allowing will need to be significantly more research in this area for a more targeted approach to recycling that takes ENVIRONMENTAL before the environmental impact of recycling can be less time and therefore consumes less energy than other accurately assessed. pyrolysis methods.

Khalil (2018) found that solvolysis has a greater human health impact, ecotoxicity and carbon footprint than IMPACTS. pyrolysis techniques112. However, these results should be handled with caution as in other studies solvolysis has been reported to have the lower environmental impact 54 55 ACADEMIC RESEARCH

There is a substantial body THE UNIVERSITY OF STRATHCLYDE THE UNIVERSITY OF BRISTOL of research being completed at universities and academic Research on the reuse or recycling of composite materials The Bristol Composites Institute, created in March 2017, Wind Blades Research Hub institutions around the world, has been underway at the University of Strathclyde across continues to build upon the esteemed reputation of The Wind Blades Research Hub (WBRH) is a £2.3million, several disciplines, including Mechanical and Aerospace the Advanced Composites Collaboration for Innovation investigating both the challenge five-year research partnership between ORE Catapult and Engineering, Marine Engineering, Advanced Manufacturing and Science (ACCIS) which was established in 2007. of end-of-life management for the University of Bristol that aims to help unlock larger, and Materials, and Design Manufacturing & Engineering The Institute is a world leader in the field of advanced more powerful wind turbines than ever before. The Wind fibre reinforced plastics and Management (DMEM). Some examples of these projects are: composites research, covering a wide range of areas, Blade Research Hub’s objective is to support turbine blade aimed at creating a circular such as structural design and analysis, novel materials Dynamic Hybrid Pyrolysis research that will reduce the cost of wind energy through economy. This section highlights development, nanotechnology and biomaterials. cost reductions in capital and operational expenditure and Research is currently ongoing into Dynamic Hybrid some examples of the ongoing The work is often collaborative in nature, with key increased energy yield, or a combination of these. The Pyrolysis which combines the traditional process and effort in these areas. relationships and networks established between faculties, WBRH is set up to focus on three key aspects of blade principals of a fluidised bed. This unconventional new universities around the world and major industrial research to achieve this: process aims to separate glass fibres and resin into usable partners. Examples relevant to the current work include forms for reuse. There is also investigation into the effects • Enabling 10MW-plus turbine platforms to come the University’s partnership with the Offshore Renewable of adding a metal catalyst to the thermal recycling of to fruition through advances in blade design and Energy (ORE) Catapult under the Wind Blades Research glass fibre reinforced epoxy. A copper oxide (CuO) nano- structural modelling, reducing blade loads and Hub (and a milestone invention by a Bristol University powder has been integrated with epoxy to assess its facilitating the transition to longer, larger blades team of High-Performance Discontinuous Fibres ability in reducing thermal stability, in turn reducing the without losses in operational performance. (HiPerDiF). typical temperature required for the thermal recycling • Improving the longevity and structural integrity process. It was found that the addition of CuO enabled of blades by developing the next generation recycling at 400°C with a yield of up to 59%, as it reduces of materials tailored to operational conditions, the epoxy matrix decomposition temperature by up to preventing degradation and maximising aerodynamic 120°C to produce the same yield without the copper performance. oxide114. • Maximising operational performance through novel Remanufacturing Processes condition monitoring methods which identify blade A variety of treatments have been investigated for damage and performance degradation. maintaining or regenerating the strength and surface HiPerDiF (High Performance Discontinuous Fibre) functionality of recycled glass fibre from decommissioned wind turbine blades. It was found that soaking recycled The HiPerDiF method has been in development at the fibres in a sodium hydroxide (NaOH) solution and silane University of Bristol since 2012 and has proven to be an treatments could restore the interfacial shear strength effective way of aligning fibres of varying lengths (from between the glass fibres and epoxy, increasing the tensile 1mm up to 12mm). The current scale-up work is funded strength of the glass fibre by up to 130%97. by a grant from the European Technology and Innovation Platform on Wind Energy (EPSRC) that was awarded in Recycling Composite Wind Turbine Blade for 2017. The project is examined in more detail in the next High-Performance Composite Manufacturing section of the report. This project aimed to develop a commercially competitive, cost-effective recycling process for large-scale recycling of wind turbine blades, with a focus on reducing the energy demand of the recycling process, improving the quality of reclaimed fibres, and improving their manufacturability115. 56 57

THE UNIVERSITY OF NOTTINGHAM THE UNIVERSITY OF LEEDS

Fluidised Bed Process Development A current feasibility study focusses upon an advanced Offshore wind research at the University of Leeds is Offshore Wind Material Inventory hydrodynamic fibre alignment process118 that allows characterised by a high degree of interdisciplinarity, whole The Composites Recycling Group at Nottingham The £450,000 Undermining Infrastructure Project composites with high-fibre content to be manufactured system approaches and co-production with stakeholders. University was initiated in the early 1990s in collaboration developed a model to analyse the criticality of materials at lower moulding pressures and with minimised length with car manufacturer Ford to demonstrate the end-of-life Research and Innovation Priorities for Low-carbon for low-carbon infrastructure, showing that the degradation. It is possible to achieve high-fibre volume compliance of glass and polyester body panels. Although Infrastructure Circular Economy dynamics of criticality – and less so the actual criticality content with competitive mechanical properties at almost the research themes are applicable to multiple sectors, – are challenging to manage for practitioners, as was 100GPa tensile modulus and over 800MPa tensile. Further In 2017-2018, a collaboration between the £7 million there is a clear leaning towards aerospace and automotive demonstrated by an offshore wind case study123. This study work is ongoing to verify this initial outcome. from Waste programme, the applications. Led by Professor Stephen Pickering, also demonstrated how the optimal mix of low-carbon University’s Cities research group and Innovate UK this group pioneered the development of a fluidised TARF-LCV: Towards Affordable, Closed-Loop Recyclable infrastructure deployed depends upon the particular delivered a research and innovation agenda for circular bed recycling process that is capable of processing Future Low Carbon Vehicle Structures technical and social context of a region. One example economy and the end-of-use management of low-carbon contaminated and mixed waste from components116. This is that the deployed infrastructure has to match that Led by Brunel University, this TARF-LCV programme infrastructure with stakeholders in government and pioneering work led to a major collaboration with Boeing available for both operations and maintenance (O&M) and (2011-2016) brought together a consortium of eight industry as well as research and innovation organisations. in 2012, with the company investing over USD 3 million end-of-use management124. research teams, including the University of Nottingham into building a commercial scale, fluidised bed pilot plant Six low-carbon infrastructure sectors (solar photovoltaics, and 17 other UK academic institutions as well as leading The Resource Recovery from Waste programme carried on the Nottingham campus. The fluidised bed process heat, grid, electric vehicles, onshore and offshore global automotive manufacturing companies. It received out a study on low-carbon materials in three parts2: has now been developed at commercial scale, and the wind) were prioritised and eight cross-cutting issues £4.2 million funding from the European Technology recovered recycled fibres have been demonstrated to be identified: (1) Value and critical materials; (2) Resource 1) The criticality of materials that are required to sustain and Innovation Platform on Wind Energy (EPSRC). The of a desirable reuse quality. recovery infrastructure; (3) Inventory; (4) Durability; offshore wind growth ambitions were analysed within project’s main themes included holistic vehicle design and (5) Whole-system analysis; (6) Skills and expertise; (7) the context of materials demand for broader low Solvolysis at Atmospheric Pressure and Hydrodynamic closed-loop recycling of vehicles with focus areas on the Policy, regulation and legislation; and (8) Economics and carbon infrastructure. Fibre Alignment development of closed-loop recyclable aluminium (Al) and business models122. magnesium (Mg) alloys, metal matrix composites (MMCs) 2) The exact volumes deployed in offshore wind in the While the processes of pyrolysis and fluidised bed have and recyclable polymer matrix composites (PMCs) for The results were integrated into ORE Catapult’s UK were inventoried. been extensively investigated and developed, oxidation 119 and 110 body structure and powertrain applications . Offshore Wind Innovation Hub (OWIH) technology remains a challenge, as it can significantly reduce the 3) Decommissioning programmes were reviewed and innovation roadmaps. fibre’s mechanical strength. To overcome this, the group Environmental and Economic Assessment of Carbon concluded that waste management procedures have also investigated alternative processes involving Fibre Recycling Technologies and Markets are unnecessarily underdeveloped, focussed upon solvolysis at atmospheric pressure to establish if the the lower regions of the waste hierarchy instead of In addition to experimental and computational research polymer could be successfully removed from carbon fibre planning to maximise values, and create high cost 117 in recycling processes, research is also underway on the within a short time , leaving cleaner individual filaments uncertainty, with most of these issues rooted in poorly development of applications for use of recycled carbon that lend themselves for manufacture into high-grade positioned decommissioning legislation. fibre and comparative analysis of their environmental and applications such as structural reinforcement. While economic viability120,121. the mechanical properties of the fibre were found to be retained to 90% of their virgin properties, the process is yet to be optimised in terms of the production costs and environmental impact associated with solvents and catalysts used. 58 59

Circular Economy and Decommissioning Governance Integrated Geoscience, Engineering, Materials THE UNIVERSITY OF HULL INTERNATIONAL INSTITUTIONS and Modelling The University of Leeds is collaborating and engaging with devolved governments and a range of UK The University has a combined geoscience, engineering, The University of Hull set up the Aura Consortium in There are many more academic and research institutions government departments. The most notable materials and modelling expertise that can be applied to: 2015 in order to innovate and collaborate in offshore around the world currently investigating the challenges of policy-focussed outputs are: wind projects covering the full spectrum of technical, wind turbine decommissioning, composite recycling and • Site investigation for substrate and seabed mobility operational, economic and societal issues. The Aura brand, the circular economy, notably: • A policy and practice note on the recovery of and impact on foundation stability and degradation, which the University leads, has since grown to include: materials from legacy landfills and closed mines, including monopile design interaction with seabed, • DTU (Technical University of Denmark) an Aura Innovation Centre (AIC) that aims to turn which are used in the manufacturing of low-carbon open data system development and the development carbon-reducing business ideas into reality; the Aura infrastructure components. of repowering strategies. • Georgia Institute of Technology Doctoral Training (CDT) which provides funded PhD • A framework repositioning circular economy to open • Material durability and fatigue testing for composites, scholarships in the offshore wind industry; and the • City University of New York up the concept to include the sourcing of materials concrete and steel, test accelerated ageing of small Offshore Wind Library (OWL), an online resource for • University of Tennessee and the full scope of end-of-use management pieces, ageing models to predict lifetimes, and digital industry-related research. strategies including the reintegration of materials into image correlation equipment for remote monitoring • Technische Universität Dresden The University is now partnering with ORE Catapult in natural biogeochemical processes, demonstrated with of turbines and measuring impacts (e.g. of vibrations its Circular Economy for the Wind Sector (CEWS) joint a case study on steel for offshore wind125. on turbine components). • Leibniz University Hannover industry partnership, investigating areas for innovation • A policy brief with Lord John Prescott entitled • Design for reuse and repowering from a geoscience in the lifetime extension, repowering, end-of-life • Fraunhofer Building Future Industries on the Strength of and structural perspective and modular design to management and decommissioning of wind farms. the Humber126. enable reuse and repurposing of North Sea oil and From Textile Waste to Advanced Carbon Materials gas infrastructure for the energy transition. • Consultation responses, such as Offshore renewables for Wind Turbine Blade Manufacturing decommissioning guidance for industry: proposed The University is also a global leader in Concrete Carbon fibre reinforced polymers are normally within updates (2018), Marine Scotland Offshore Science and has the facilities to investigate a variety the ‘spar’ of a turbine blade, as this is the primary load renewables decommissioning guidance (2020) of applications relevant to blade recycling, such as: bearing component and benefits from their high tensile, and the Environmental Audit Committee’s the use of mechanically processed blade pieces as compression strength, low weight, and anti-corrosion Technological Innovations and Climate Change: alternative aggregates; use of fibres recovered after properties. This project has explored the utilisation of Offshore Wind (2020). pyrolysis in concrete; processing blades into synthetic textile waste as a raw material for nano-carbon filament sand replacements (or even smaller particles) as • Several workshops, meetings and ad hoc interactions production and consequent application as a filler. partial synthetic substitutes of cement (i.e. cement to offer immediate advice to government. co-processing); and thermal treatment using blades The project also aims to address the cost efficiency of as fuel for the production of cements. bulk blade material production and low carbon transitions by optimising waste management and decreasing This research is augmented by the University’s broad the volumes of waste sent to landfill127 offshore wind expertise. Current research into offshore . Two modern wind is progressing via a project with the Engineering techniques in nanomaterials manufacturing are being used in combination: and Physical Sciences Research Council (ESPRC) titled A Sustainable Circular Economy for Offshore Wind. • Thermal Chemical Vapour Deposition (TCVD) technology, which can produce versatile nanostructured carbon filaments from waste textiles.

• And carbon filaments processed by an electrospinning technique that produces nano / microfibrous carbon fibre reinforced plastic. 60 61 INDUSTRY INNOVATION PROGRAMMES

CIRCULAR ECONOMY FOR A SUSTAINABLE CIRCULAR SUSWIND MOONSHOT CIRCULAR THE WIND SECTOR JOINT ECONOMY FOR OFFSHORE WIND WIND FARMS INDUSTRY PROJECT SusWIND was launched in October 2020 and is designed The project was initiated in August 2020 and will run up to be a multi-year programme across three waves Launched in August 2020, the Moonshot project is funded of activity. Coordinated by the National Composites ORE Catapult’s Circular Economy for the Wind Sector to the end of March 2021. It has a budget of £78,277, co- by the Dutch Ministry of Economic Affairs and Climate Centre, the project’s launch partners include Vestas, SSE (CEWS) JIP was established to investigate new solutions funded by the Engineering and Physical Sciences Research Policy. Details of the budget have not been made public. Renewables, the Crown Estate, Shell, BVG Associates, for the bulk recycling of wind turbine blades and conduct Council (EPSRC) and the project partners are the ORE Partners are the main funder together with the Dutch RenewableUK, OGTC and ORE Catapult. techno-economic analysis of their suitability for large- Catapult, Department for International Trade (DIT) and the Ministry of Infrastructure and Water Management, VNO- scale redeployment. CEWS has targeted an at-scale University of Leeds. The budget is flexible depending on member NCW, MVO Nederland and Het Groene Brein. demonstration of wind turbine blade recycling in the This knowledge transfer project aims to start to integrate contributions with additional funding drawn from the The aim of the project is to find solutions to preserve UK within the next five years. circular economy into offshore wind infrastructure Sustainable Composites Initiative (a partnership between critical materials from wind farms in the resource cycle the National Composites Centre and the Centre for As part of this project, ORE Catapult aims to lead and design, operation and end-of-use management. A series and form a basis for new business cases in wind farm Process Innovation - CPI). facilitate the development of industry best practice and of outputs are being delivered such as industry and circularity. By transforming the wind industry into a the supporting tools for the detailed understanding government events, policy and practice briefings, and SusWIND’s goal is to establish a more circular and circular driven value chain where the necessary resources of true end-of-life potential for pilings, to reduce the a framework for circular economy in offshore wind and sustainable future for wind turbine blade technology. can be maximised and more efficiently utilised, the project environmental and ecological impacts. As well as the baseline of current circular practices. It also supports aligns to the Dutch Government’s targets of at least 50% There are three waves of activity: reuse, recycling or sustainable disposal of decommissioned knowledge exchange across low-carbon energy, oil & gas less virgin material usage (minerals, metals, and fossil) by and offshore wind sectors, and prepares the ground for a 2030 and no virgin material usage by 2050. offshore wind turbines, CEWS aims to lay the foundations Wave 1 is designed to stimulate the supply chain five-year joint industry partnership on circular economy of a new circular economy supply chain for the sector, for blade recycling and find ways of leveraging and wind systems. The project’s objectives are to: allowing wind turbine components to be disposed of in the broader supply chain for composites in other the best possible way. • Raise awareness of the added value of circular sectors. Work packages include landscape mapping, exploitation routes for upscaling viable technologies The project will focus on four key areas: economy approaches for offshore wind; and demonstration of the effective use of recycled • Blade Recycling • Develop strategic responses to the forecasted steeply materials in value-add products for other applications. rising levels of criticality of materials on which • Cost Strategy offshore wind growth is dependent; Wave 2 will demonstrate options to reduce the environmental footprint of blade manufacture • Monopile Remaining Useful Life (RUL) • Identify business opportunities and circular business through the use of more sustainable and lower impact models to increase the sustainability potential of • Recycling Route Map material feedstock, and through minimising or recycling offshore wind. waste streams.

Wave 3 will develop robust guidelines to improve design for end of life, ensuring waste is minimised and that composite components can be disassembled for cost effective repair, reuse, remanufacture and recycling. 62 63

Figure 19. RE-WIND Design for a Pedestrian/Cyclist Bridge by the Re-Wind Project The project’s start date was June 2017 and has since The Re-Wind project is currently working with Cork been extended beyond its planned 36 months. Work County Council to design a short span pedestrian/ is supported by grants from Invest Northern Ireland cyclist bridge using two decommissioned blade sections (under the Department for the Economy - DFE), (Figure 19). Under an additional project, the consortium Science Foundation Ireland and the US National Science has been experimenting with use of large blades in the Foundation. Project partners are Georgia Institute of construction of emergency housing or shelter rooftops Technology, Queens University Belfast, the City University (Figure 20). Structural analysis results have been of New York and University College Cork. promising: the biggest challenge identified is related to building permissions rather than the blades themselves. The Re-Wind project brings together multiple academics There are as yet no government building codes for from the USA and Ireland focusing on reuse and recycling structures made out of fibre reinforced plastics in this way. of wind turbine blades, with the emphasis being placed upon reuse. The solutions proposed consist of reusing The last type of blade repurposing being investigated by entire fibre reinforced plastic blades (or large parts of the Re-Wind project is their use as transmission line poles them) in new structural applications. Besides identifying (Figure 21). Static analysis of critical load cases indicate reuse opportunities, the project will also model turbine that the blade can easily resist the expected loading, and blades to establish their load history and better future project activities will now focus on the experimental understand their residual strength and appropriate uses. validation of the product.

Figure 21. Design Prototype for Transmission Line Poles Made from Used Wind Turbine Blades

Figure 20. 40m2 Housing Constructed with Roof from 100m Blade

Roof frame Doors and shutters

Platform foundation Roof panels 64 65

INTERNATIONAL ENERGY AGENCY The HiPerDiF project has developed a new process for ECOBULK EURECOMP layup and alignment of carbon fibre tape from recycled WIND TASK PROPOSAL waste materials. The process uses a water stream to enable the suspension of fibres, which are then diverted The project runs from June 2017 to May 2021 using €12 million The EURECOMP project ran from May 2009 to July 2012 A project proposal has been submitted to IEA Wind for a through nozzles into gaps between parallel plates to align funding from the European Union’s Horizon 2020 Research with an overall budget of €2.5 million including an EU them. The number of nozzles and alignment plates can be and Innovation Programme under Grant Agreement No contribution of almost 2 million. The aim was to develop a €54,000 three-year programme that would be led by the € Technical University of Denmark (DTU), National Renewable varied depending on the required width of tape. The fibres 730456. Partners cover an extensive number of European route for recycling fibre-reinforced thermoset composites Energy Laboratory (NREL), University College Cork and the then fall onto a conveyor belt where water is removed by academic institutions, research bodies and industries. and commercialise recycled components from cars and suction and the aligned fibre preform is dried using infrared boats. During the project, a prototype of a solvolysis reactor University of Leeds. The purpose of the proposed project ECOBULK is, as the name suggests, a large-scale radiation. The dried preform is then coupled with a resin was developed (4ml to 1,000ml reactor capacity) and the is to identify and mitigate the barriers to recycling wind demonstration project. The preliminary demonstration spans film and partially impregnated through the application of parameters were studied (temperature, processing time, turbine blades with a focus on three main areas: a total of seven EU-countries, comprising 11 demonstrators heat and pressure to form a prepreg tape99. Aligned mats pressure, chemical to composite ratio, etc). The first results that will conduct 21 individual demonstrations within the • The technical aspects of recycling wind turbine blades can also be produced99. showed that solvolysis allows the removal of up to 90% of three target product sectors: automotive, furniture (indoor/ resin and retrieval of liquids, such as benzoic acid, that have • Analysis of the recycling value chain and the outdoor) and construction. Previous studies have indicated that the tensile modulus, a commercial application. environmental, social and economic impact strength and strain at failure of the aligned material One of the demonstrations is recycled glass fibre reinforced produced by the HiPerDiF process were close to those of The second phase of the project built a large scale solvolysis • Standards, certification and legislation framing the polymers from wind turbine blades, the first thermoplastic continuous virgin carbon fibre, providing a high level of reactor with a capacity of 20 litres. Recovered fibres activities related to recycling wind turbine blades composite to incorporate it as a reinforcing material. Below alignment and fibres that meet the critical fibre length. maintained 60% of the maximum mechanical performance is a summary of the demonstration products and activities: Through a structured forum for international collaborations Another benefit of this process is that material can be of virgin fibres. They were reprocessed into a prototype of between researchers, industries (wind industries, recyclers, reprocessed multiple times99. 1. Design and manufacture of easy-to-replace and an electrical box using 20% recycled content and 80% new material provider and more) and associations, the project refurbished internal car parts from recycled plastics fibres which was proven to achieve the required mechanical aims to produce recommended practices and guidelines performance. However, truck parts that were manufactured that can be used by practitioners. 2. Development of new resins for particle board furniture from 20% recycled fibres showed degradation of material STEAM TO VALUE STREAM with lower formaldehyde concentration following mechanical testing.

3. Production of weather resistant extruded composite The project’s partner organisations were: WindEurope, Initiated in June 2020, the project is funded through the components for outdoor benches and tables from Cefic and EuCIA, British Plastics Federation, Plastic Omnium HIPERDIF (HIGH PERFORMANCE Sustainable Composites Partnership (National Composites recycled plastics and waste wood fibres Auto Exterieur, University of Exeter, Volvo Technology DISCONTINUOUS FIBRE) Centre and Centre for Process Innovation - CPI) and adds Corporation, University of Bristol, Xietong Automobile Longworth as a project partner. 4. And use of wind turbine blade composites to create Accessories, COMPOSITEC, SACMO, ECRC (European extruded composite profiles and panels for structural This project initiated in December 2017 and is due to run Composites Recycling Services Company), URIARTE Research focusses upon the opportunities for using super- applications (various type of shelters and cabins) until June 2021. It received £1,036,426 of funding from the critical steam to reclaim high performance fibres and Safybox, ICAM Nantes, GAIKER and the University of UK Engineering and Physical Sciences Research Council investigates whether the same process can recover some of The consortium members are: VERTECH GROUP (VTG), Limerick. (EPSRC) for a period of three years. the matrix material from glass and carbon fibre reinforced Polytechnic University of Catalonia, Spanish Association for Standardisation, Delft Technical University, TOMRA, The University of Bristol leads the 10-strong consortium composites. TECNARO, ITENE, Next Technology, Microcab, MAIER, which also includes: Airbus Group, BAE Systems, Coriolis The DEECOM ® process uses a combination of superheated Intermunicipal Waste Management of Greater Porto (LIPOR), Composites UK, ELG Carbon Fibre, Hexcel Composites, steam pressure swings or compression/decompression Kneia, Kastamonu Entegre (KEAS), International Solid Waste Hitachi, Oxford Advanced Surfaces, Solvay Group (UK) and cycles to remove polymer resins and reclaim fibres, Association (ISWA), IRIS, Italian National Research Council Toyota. maintaining their tensile strength and mechanical (CNR), Exergy, Granta Design, Moretti Compact, French performance properties so that they can be reused for Institute of Technology for the Forest-based and Furniture remanufacture. Sectors (FCBA), Research Center Fiat, Cranfield University, Conenor, Coventive Composites, Aimplas, AkzoNobel, BELLVER PLA GROUP, Oakdene Hollins and Technoplants. 66 67

FIBEREUSE

This €9.8 million research project funded by the 1. Macro use-case 1 (represented by the pink stream in European Union (GA No. H2020-730323-1) has been Figure 22) is the mechanical recycling of short glass fibre running since June 2017. It aims to enhance the profitability reinforced plastics and reuse in added-value customised of recycled glass and carbon fibre and their reuse in applications such as furniture, sport and creative value-added products by holistically integrating different products. It includes demonstration of manufacturing innovative solutions. Three macro use-cases are fuelling technologies such as UV-assisted 3D-printing and eight demonstrators: metallisation by physical vapour deposition.

2. Macro use-case 2 (represented by the green stream) is thermal recycling, via controlled pyrolysis, of long glass and carbon fibres from end-of-life wind turbine and aerospace components for reuse in high-tech, high-resistance applications in the automotive LIFE-BRIO GENVIND PROJECT REROBALSA (aesthetical and structural components) and building sectors via custom remanufacturing methods. LIFE-BRIO brought together Iberdrola, The GenVind project ran from June The project ran from August 2017 3. Macro use-case 3 (represented by the yellow stream) Gaiker-Ik4 and Tecnalia and ran from 2013 to November 2016 with funding of to June 2019 with funding from the is the inspection, repair and remanufacturing of July 2014 to June 2017 with a total DKK 43.5 million (just over €5 million German Federal Ministry of Education carbon fibre reinforced products in high-tech budget of €1,107,626, including EU in today’s values), including a grant and Research (BMBF). It was applications with adaptive design and manufacturing funding of €553,812. The project from the Danish Agency for Science, coordinated by Fraunhofer Wilhelm- for a complete circular economy demonstration in the investigated and demonstrated Technology and Innovation. The 25 Klauditz-Institut, and other partners automotive industry. sustainable end-of-life methodology for consortium members included Danish included the Technische Hochschule each stage of blade decommissioning, companies in the wind turbine industry, Nürnberg (Nuremberg Tech), MATETEC, The project partners are drawn from seven EU countries including rotor blade dismantling, the building sector and the colour/ Kovalex GmbH, BINOS GmbH, and include: the University of Strathclyde, Novellini, Tecnalia, material resources recovery and lacquer industry: Technical University Sachverständigenbüro Otto Lutz, Mau Siemens Gamesa, Batz, Maier, Aernnova, Fraunhofer, Figure 22. incorporation of recovered materials into of Denmark (DTU), Aalborg University und Mittelmann GmbH, Airex AG, 3A Edag, Invent, Avk, Tampere University of Technology, FiberEUse use-cases and industrial new products. Esbjerg, University of Nottingham, Composites Core Materials, Schweiz, rub Head, Saubermacher, Design Austria, Politecnico Milano, sectors involved128 Danish Technological Institute, and Berlin – Gesellschaft für Recycling and Foams and supports were separated Rivierasca, Holonix and GreenCoat. FORCE Technology as well as the Umwelt und Biotechnologie GmbH. from the main composite content before Danish Plastics Federation. going through mechanical recycling The main objective of this research (shredding) for a combination of long The goal of the project was to identify project was the development of fibres and short fibres with polymer. new strategies for sustainable recycling an innovative recycling technology After separation of the two, the long of composites and develop existing for the recovery of balsa wood and fibres could be used as filler material in ones. The consortium also aimed plastic foam from rotor blades. It Creative Furniture products Construction Sport Wind Aerospace Auto precast concrete, while the shorter fibres to develop enabling technologies also developed innovative recycling could be used as cores for multilayer for a sustainable recycling of plastic technologies for use of recyclates in structures. composites and demonstrate that insulation and building materials. waste can be used in many different Blades were supplied through the Key outputs included: reuse of balsa products, components and structures. decommissioning of Coal Clough wood during wind turbine dismantling Products that were manufactured from Wind Farm in the UK (24 Vestas at location; ultra-lightweight wood waste plastic composites were furniture, WD34 turbines): 5.6% of the blade’s fibre insulation mats; and extruded building panels, noise barriers, new composition was metallic and was floorboards mode from wood polymer wind turbine blades, paints, textiles, provided for smelting, 43.9% of the composites (WPC). fibre reinforced concrete, mortar and blades structure was recycled as brick, stronger concrete and plastic reinforcement in concrete, and 50.5% constructions. GFRP CFRP (short fibres and polymer) was used to make thermoset and thermoplastic multilayer panels129. All the resulting products had their performance tested. The concrete’s performance showed improvement while reducing the use Custom Custom of both concrete and aggregates and reforming remanufacturing without altering the manufacturing process. The panels showed a similar mechanical performance to panels made Mechanical Thermal Inspection of non-recycled materials. recycling recycling repair The project also offered guidelines for GFRP = glass fibre reinforced plastic more specific regulation regarding wind CFRP = carbon fibre reinforced plastic turbine decommissioning. 68 69

DECOMTOOLS ELIOT RECY-COMPOSITE CARBO4POWER

DecomTools has run since December 2018 with €4.7 million ELIOT launched in July 2020 and will run for a duration The project was initiated January 2016 and ran until Carbo4Power is a four-year project that is funded by funding from EU’s Interreg North Sea Region Programme. It of 32 months with funding from the EU’s Horizon 2020 September 2020 with a budget of €3,180,556 (including the EU’s Horizon 2020 programme. Led by the National formed part of a whole system investigation into end-of-life programme. Partners are AIMPLAS and TNO (Dutch €1,590,278 from the European Regional Development Technical University of Athens (NTUA), it comprises a management of offshore wind farms. The aim was to devise Organisation for Applied Scientific Research). Research Fund under the “Interreg V-A-Belgium-France (France- network of academic and industrial partners drawn from and develop eco-innovative concepts that would reduce is aimed at developing novel cost-effective recycling Wallonie-Vlaanderen)” Operational Programme for across Europe, including ORE Catapult. decommissioning costs by 20% and environmental footprint technologies that will guarantee the sustainability of 2014-2020 130. The project partners were Certech, Crepim, Carbo4Power will develop a new generation of lightweight, by 25% (measured in CO2 equivalents) while increasing the aeronautics components. Different recycling methods VCK-Centexbel, CTP and Mines de Douai – Armines. high-strength, multifunctional, digitalised multi-materials for know-how and expertise of stakeholders. are being analysed, including mechanical, thermal, The project was set up meet the challenge of composite offshore wind and tidal turbine rotor blades that will increase chemical and biological recycling. The thirteen European partners include: Hamburg Institute materials recycling through a three-level, cross-border their operational performance and durability while reducing of International Economics (HWWI), University of Applied approach that comprised: the cost of energy production (below 10ct€/kWh for wind Sciences (UAS), FYNS Maritime Klynge, New Energy Coalition, turbines and 15ct€/kWh for tidal), cost of maintenance 1. Material recovery Western Norway University of Applied Sciences, Port of DREAMWIND and their environmental impact. The innovative concept is Grenaa (Denmark), POM, De Lavwershorst Groep, Samso 2. Thermochemical recycling (pyrolysis, solvolysis) based on nano-engineered hybrid (multi)materials and their Kommune, University of Aberdeen, Port Oostende, Energy intelligent architectures. Dreamwind ran until March 2020 under a grant of DKK Innovation Cluster and Virol. 3. And energy recovery (only as a last resort) 17.6 million (€2.3 million equivalent) from the Innovation The project foresees the following results: Fund Denmark. Partners were Aarhus University, Danish Technological Institute and Vestas Wind Systems. 1. Nanocomposites based on dynamic thermosets with SPARTA ETIPWIND inherent recyclability and repairability and tailored Researchers developed a chemical to enable the nano-reinforcements to enhance mechanical properties. separation of composite materials within wind turbine The SPARTA project runs for two years and launched in blades, allowing for easier recycling opportunities. The The European Technology and Innovation Platform on 2. Multifunctional nano-enabled coatings to improve Wind Energy (ETIPWind) is funded by the EU’s Horizon turbine protection (e.g., against lightning and September 2020 with funding of €349,542 from the EU’s separated glass and carbon fibres can then be cleaned Horizon 2020 programme. It is led by the Technological and reused in the manufacture of new components. 2020 programme and was originally established in 2016 to biofouling). Institute of Plastics (AIMPLAS) and the Tekniker Research and Possible reuses have been highlighted within the wind, inform research and innovation policy at both a European 3. Blade segments that will be designed and fabricated Technology Centre. automotive and aerospace industries. and national level. ETIPWind activities combine two by advanced net-shape automated multi-material prior initiatives: the European Wind Energy Technology composite technologies that will allow ca. 20% scrap The objectives are to find more efficient methods of recycling Platform and the European Wind Industry Initiative. By reduction. and reprocessing composite thermoplastic materials and to providing a public platform for wind industry stakeholders design more eco-efficient manufacturing methods. The project to identify common research and innovation priorities, 4. An innovative design of modular rotor blade and an includes development and optimisation of an innovative ETIPWind fosters breakthrough innovations in the sector optimal design for ‘one-shot’ manufacture. mechanical scrapping process and attempts at improving and communicates these to European institutions and material reprocessing through automatic deposition and decision-making bodies in order to support progress to 5. Increased recycling of blade materials by up to 95% compression moulding. a decarbonised economy by 2050. due to the advanced functionalities of 3R resins and adhesives with debonding on demand properties. This method will make it possible to use up to 80% of current ETIPWind also contributes to the European Strategic aerospace waste compared to other mechanical recycling Energy Technology Plan (SET-Plan), an initiative that methods and cut processing times by as much as 50%. aims to accelerate the development and deployment This will be achieved by reducing the number of steps in of low-carbon technologies by coordinating national waste recovery, using more efficient automatic reprocessing research efforts and helping finance projects. The SET-Plan 2 methods, reducing CO emissions up to 30% through the use promotes research and innovation efforts across Europe of waste and curb production demand for virgin material. and supports the most impactful technologies for the transformation to a low-carbon energy system. The role of ETIPWind is to give recommendations to policymakers on how to improve new technologies and reduce costs. This includes an energy road map131 and strategic research into wind turbine blade circularity6. 70 71

ZEBRA (ZERO WASTE BLADE FIBROUS GEOCYCLE BY LAFARGEHOLCIM for the deployment of a full-scale commercial wind blade waste processing plant to recover both the glass fibre for RESEARCH) recycling into new composite applications and the organic The project was initiated by TNO, the Dutch Organisation Launched in 2017 by LafargeHolcim, Geocycle is now a components which can be turned into useful petrochemicals ZEBRA launched in September 2020 and will run for a period for Applied Scientific Research, in 2020. The current budget global commercial enterprise. Its key achievement is the for energy production. of 42 months under a 18.5 million budget. Its aim is to design is unknown, but it submitted for additional funding to the development of a process for a sustainable recycling of used € The participating companies are: Carbon Rivers, a start-up and manufacture the world’s first 100% recyclable wind turbine HER+ subsidy programme at the end of 2020. The objective rotor blades. The service starts with a first cut and collection company owned by Tennessee University alumnus Bowie blade132 and to demonstrate a full-scale, technical, economic is the development of a cost-effective and sustainable end- of rotor blades at a wind turbine site, complete incorporation Benson; GE Renewable Energy; Berkshire Hathaway Energy’s and environmental thermoplastic wind turbine blade, eco- of-life solution for fibre-reinforced composite wind turbines of rotor blade ashes into the clinker matrix (material MidAmerican Energy Company and PacifiCorp utilities. designed to facilitate recycling. blades used at offshore wind farms. recovery) as well as use of the thermal energy content of the blades (thermal recovery). In this way, it saves natural The chosen recycling technology is pyrolysis because of The project has representation from across the full value chain, resources by substituting primary raw materials (like sand) its high maturity level and the ability to extract carbon and including the development of materials, blade manufacturing, and fossil fuels. SER wind turbine operation and decommissioning, and recycling glass fibres from the blades for reuse. This technology will be of the decommissioned blade material. Project partners are: developed for processing large blade sections and large fibre To avoid the need for transport with special permits, a Arkema, Engie, LM Wind Power, Owens Corning, SUEZ, CANOE length (2m+). The end product cost will be optimised to mobile cutting technique, similar to concrete dismantling Under SER, the European wind industry has been engaged and the Jules Verne Institute for Technological Research (IRT). meet Europe’s rapidly growing need for sustainable circular procedures, breaks down large-scale components into in dialogue with other stakeholders to reach an international solutions for the volumes of wind turbine blades reaching smaller fragments on site or the intermediate storage Responsible Business Conduct agreement for the wind the end of their useful life. areas. The humidification of the cutting location secures a sector, which they aim to sign before summer 2021. The maximum reduction of generated dust. The sawdust is then dialogue concerns not only composites, but the entire value The partner organisations are Fairphone, Appletree, Enerpy, SURFACE collected and returned to the material flow of the treatment chain of the wind industry. Virol, ITRI, Port of Amsterdam, Groningen Seaport, Shell, plant. After this preparatory step, the fragments are shipped Amsterdam Ijmuiden offshore ports and Suzlon. The industry’s goal is to identify, prevent and address risks to This project is currently under proposal. The grant application in lengths of 10m to a recycling plant in Melbeck. people and the environment across the entire supply chain, is to the Mission-driven Research, Development and Innovation Automated saws cut the turbine blades into pieces of about from risks related to the extraction of raw materials for wind subsidy scheme (MOOI) subsidy scheme. The coordinating 1m in length. Shredder units then crush the components in turbines through to the decommissioning of wind farms. partner of a 23-strong consortium is TNO (Dutch Organisation DEMACQ RECYCLING an encapsulated system into pieces less than 50mm long. for Applied Scientific Research). INTERNATIONAL The thermal energy content of the waste stream is used as a The intention is to commit the parties to implementing the Organisation for Economic Cooperation and Development’s The aim is development of a cost-effective and sustainable fuel substitution at around 900°C for the calcination process Guidelines for Multinational Enterprises and the UN’s Guiding end-of-life solution for fibre-reinforced composite wind turbine This project was initiated in September 2016 and there is of raw material. The accrued ashes are then combined with Principles on Business and Human Rights (UNGPs) in their blades using pyrolysis to extract carbon and glass fibres for little public information on its continued activity (which the calcinated raw materials in the sintering zone of the operations and throughout their supply chains. reuse. The project will research the capability of processing ceases after 2019). The budget is unknown as it appears to cement kiln. Finally, the clinker is ground together with a small amount of gypsum to make the cement. large blade sections and longer fibre lengths (2m+). have been a commercial venture launched by Demacq in At this stage, they will explore how to identify and address partnership with NWEA and DWP System Supplier. the risks for people and the environment in the supply chain of the wind energy sector before offering shared solutions The work was based upon Demacq Recycling International’s to address problems that companies cannot solve entirely breakthrough in finding a way to dismantle large composites UNIVERSITY OF TENNESSEE BLADE by themselves. To increase their leverage, organisations will in a sustainable way and give them a new use, such as in RECYCLING PROGRAMME actively pursue collaboration with international initiatives shore protection. that share their goals. In September 2020, the University won USD 1.1 million of funding from the Department of Energy (DOE) Small Partners are WindEurope, NWEA, NVDE, TKI Wind op Business Technology Transfer (STTR) programme and Wind Zee, Eneco, Engie, RWE Renewables, Ørsted, Vattenfall, Energy Technologies Office. ENERCON, MHI Vestas Offshore, Siemens Gamesa, Van Oord, Action Aid, the North Sea Foundation, FNV, The programme aims to develop a new technology for the Dutch ministries of Foreign Affairs and Economic large-scale recycling of wind turbine blades into new Affairs and Climate Policy, Pels Rijcken and the SOMO recycled composites. This will be a pilot-scale glass fibre knowledge centre. composite recycling system that will serve as the basis 72 73 RECOMMENDATIONS AND NEXT STEPS

CONCLUSION 1 CONCLUSION 2 CONCLUSION 3 NEXT STEPS

Carbon fibre recycling at scale will The approach to R&D needs to shift Wind turbine blade recycling will only From an economic perspective, we have a confluence pave the way for advances in glass to focus on the supply chain that will be achieved by leveraging the diversity of recycling technologies on the cusp of commercial viability and an urgent requirement by industry. Composite fibre recycling. produce the end products rather than of active R&D projects on composites recycling can be seen as the first step towards creating an the production of recyclates with no across different sectors. Our view is that carbon fibre recycling at scale for advanced circular economy that will serve UK industries clear destination. and yield exportable IP, services, skills and technologies. wind turbine blades will be feasible within five years. The study has highlighted 28 major collaborative R&D ORE Catapult’s Circular Economy for the Wind Sector We have discussed the definition of ‘recycling’ and projects focusing on carbon and/or glass fibre composites The wind industry can play a central role in the UK Joint Industry Project JIP (CEWS JIP) is working ambiguities in its use by UK regulatory bodies. Some and numerous in-house recycling drives by the most realising these economic benefits: it is the composite user towards this target. count recycling as the recovery of a material, even if that prominent players in industries such as aerospace and that has the fastest future growth pathway thanks to its automotive. The wind sector is increasingly adding its There are two provisos: material does not go on to be used in an end product. criticality for the energy transition. Our study shows that We recommend adopting the more precise definition that considerable weight behind the development of composite the wind industry cannot solve the composites challenge • Investment in R&D must be increased to drive recycling must result in a usable end product for it to be recycling technologies: 2020 became a landmark year alone, however, and the collaborative cross-sector nature down costs and environmental impacts both environmentally and economically meaningful. Only for the launch of projects specifically on wind turbine of many of the projects studied illustrate this point. by recyclates replacing the deployment of new virgin blade recycling. • The demonstration system must receive While that is the wind industry’s ambition, the sector materials, and by delaying disposal, can environmental a steady and consistent flow of blades We recommend that the focus is on cross-sector with the strongest track record on tackling composite impact be mitigated. Likewise, the chance to increase job collaboration and finding synergies between the many recycling to date has been automotive. A great deal of the creation depends upon achieving viable end products disparate composite recycling projects summarised in stimulus has come from EU directives that have legislated from recycling. the full report. Collaboration with the oil and gas industry, environmental assessments and impact analysis. A If ORE Catapult is to achieve its target of an at-scale blade in particular, will be essential in bringing in the necessary similar situation is developing for the wind sector. Several recycling demonstration within five years, co-ordination scale of investment and prove crucial to finding good agencies are now working to investigate and develop is required with the many composite recycling projects recycling solutions. similar guidance, best practice and industry standards that are underway across the world. As our review of the for end-of-life wind turbine blades. We can anticipate current R&D landscape makes clear, the focus to date these standards being brought into local, European, and has been on producing recyclates without matching potentially international regulations in the future. these recovered materials to the supply chain needs It must be recognised that reclamation and reprocessing and ultimate products. Phases 2 and 3 of the Energy of recyclates from blade materials must also be a Transition Alliance Project and the CEWS JIP will focus on financially attractive option for the wind industry to stimulating the future supply chain for recyclates. ensure rapid adoption. That is why the next phase of the A further imperative is to raise awareness of the circular Energy Transition Alliance’s Blade Recycling Project, of economy business opportunity amongst UK supply chains which this report is just the first phase, will focus upon and policymakers. As highlighted earlier, the opportunity the environmental, social, economic and technical costs goes beyond the recycling of composites: it spans various and benefits of blade recycling. In Phase 3, we will take remanufacturing and reprocessing solutions for every wind forward the most promising technologies for development turbine component. Investment now presents a golden and demonstration. opportunity to not just support the sector’s job creation targets by 2030, but also to extend them by an estimated 20,000 jobs. 74 75

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